Organic electronic device and method for manufacturing the same

ABSTRACT

An organic electronic device of the present invention includes a substrate, at least two electrodes formed on the substrate, a conductive organic thin film that is formed on the substrate and electrically connects the electrodes, and a coating film for coating at least a portion of the electrodes. The conductive organic thin film is a polymer of organic molecules containing a conjugated-bondable group, and one end of each of the organic molecules is chemically bonded to the surface of the substrate and the conjugated-bondable groups in the organic molecules are polymerized with other conjugated-bondable groups to form a conjugated bond chain. The coating film electrically connects the electrodes to the conductive organic thin film and achieves a smaller connection resistance than that in the case where the electrodes and the conductive organic thin film are connected directly. As the coating film, a film made of metal selected from gold, platinum, and silver, a conductive polymeric film, or a monomolecular film that is chemically bonded to the electrodes can be used.

TECHNICAL FIELD

The present invention relates to an organic electronic device using aconductive organic thin film and a method for manufacturing the same.

BACKGROUND ART

Conventionally, inorganic materials, a typical example of which issilicon crystals, have been used for electronic devices. However, suchinorganic materials have a disadvantage that as the devices are madefiner, crystal defects become critical, and the device performancedisadvantageously depends largely on the crystals.

On the contrary, conductive organic thin films have been given attentionas a material that can cope with the development of deviceminiaturization because the properties of the conductive organic thinfilms hardly deteriorate even when they are subjected to fineprocessing. The applicant already has suggested organic thin filmscontaining a conjugated bond chain such as polyacetylene,polydiacetylene, polyacene, polyphenylene, polythiophene, polypyrrole,and polyaniline (e.g., JP H2(1990)-27766A, U.S. Pat. No. 5,008,127,EP-A-0385656, EP-A-0339677, EP-A-0552637, U.S. Pat. No. 5,270,417, JPH5(1993)-87559A, and JP H6(1994) JP6-92971A).

An electronic device using a conductive organic thin film (hereinafter,referred to as “organic electronic device”) generally has a structure inwhich two electrodes formed on a substrate are connected electrically bya conductive organic thin film. As the electrodes, inorganic materialssuch as metals are used. In such an organic electronic device, it isrequired that electrical connectivity between the electrodes is good,and with this requirement, there is a demand for further improvement inconnectivity between each of the electrodes and the conductive organicthin film.

DISCLOSURE OF INVENTION

An organic electronic device of the present invention includes asubstrate, at least two electrodes formed on the substrate, a conductiveorganic thin film that is formed on the substrate and electricallyconnects the electrodes, and a coating film for coating at least aportion of the electrodes, wherein the conductive organic thin film is apolymer of organic molecules containing a conjugated-bondable group, andone end of each of the organic molecules is chemically bonded to thesurface of the substrate and the conjugated-bondable groups in theorganic molecules are polymerized with other conjugated-bondable groupsto form a conjugated bond chain, and the coating film electricallyconnects the electrodes to the conductive organic thin film and achievesa smaller connection resistance than that in the case where theelectrodes and the conductive organic thin film are connected directly.

Moreover, a method for manufacturing the organic electronic device ofthe present invention includes forming at least two electrodes on asubstrate having active hydrogen on its surface, forming a coating filmon the surfaces of the electrodes, forming a precursor of a conductiveorganic thin film on the surface of the substrate such that at least aportion of the precursor is in contact with the coating film by bringingorganic molecules containing a conjugated-bondable group that can bepolymerized with other molecules and an end-bondable group that can bechemically bonded to the surface of the substrate at one end intocontact with the surface of the substrate to form a chemical bond by areaction between the active hydrogen on the surface of the substrate andthe end-bondable group, and forming the conductive organic thin film bypolymerizing the conjugated-bondable groups in the organic moleculesconstituting the precursor of the conductive organic thin film withother conjugated-bondable groups to form a conjugated bond chain toconnect electrically the electrodes via the conductive organic thinfilm.

Examples of the coating film include a metal film, a conductivepolymeric film, and a monomolecular film that is chemically bonded tothe surfaces of the electrodes.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view showing an example of an organicelectronic device according to a first embodiment of the presentinvention.

FIGS. 2A through 2G are views showing a process sequence of an exampleof a method for manufacturing the organic electronic device according tothe first embodiment.

FIG. 3 is a schematic diagram showing a structure of a monomolecularfilm that is a precursor of a conductive organic thin film in the firstembodiment.

FIG. 4 is a schematic diagram showing a structure of the conductiveorganic thin film in the first embodiment.

FIGS. 5A and 5B are schematic diagrams showing change in theconductivity of the organic electronic device in the first embodiment,and FIG. 5A is a graph showing change in current with respect to lightirradiation time, and FIG. 5B is a schematic diagram showing a switchingoperation by irradiation with two types of light having differentwavelengths.

FIG. 6 is a cross-sectional view showing an example of an organicelectronic device according to a second embodiment of the presentinvention.

FIG. 7 is a cross-sectional view showing an example of an organicelectronic device according to a third embodiment of the presentinvention.

FIGS. 8A through 8H are views showing a process sequence of an exampleof a method for manufacturing the organic electronic device according tothe third embodiment.

FIG. 9A is a schematic diagram showing a structure of a monomolecularfilm for coating in an organic electronic device according to a fourthembodiment of the present invention, and FIG. 9B is a schematic diagramshowing the structure when the monomolecular film in FIG. 9A ispolymerized.

FIG. 10 is a cross-sectional view showing an example of an organicelectronic device according to a fifth embodiment of the presentinvention.

FIG. 11 is a process sequence of an example of a method formanufacturing of the organic electronic device according to the fifthembodiment.

FIG. 12 is a schematic diagram showing a structure of a monomolecularfilm for coating in the fifth embodiment.

FIGS. 13A and 13B are schematic diagrams showing a structure of aprecursor thin film in the fifth embodiment, and FIG. 13A shows a regionon a substrate and FIG. 13B shows a region on an electrode.

FIGS. 14A and 14B are schematic diagrams showing a structure of aconductive organic thin film in the fifth embodiment, and FIG. 14A showsa region on the substrate and FIG. 14B shows a region on the electrode.

FIG. 15A is a schematic diagram showing a structure of an orientedmonomolecular film that is a precursor thin film in a seventh embodimentof the present invention, and FIG. 15B is a schematic diagram showing astructure of a conductive organic thin film in which orientedmonomolecules in FIG. 15A are polymerized.

FIG. 16 is a schematic diagram showing an angle of tilt orientation ofan organic molecule with respect to a substrate in the seventhembodiment.

FIG. 17 is a cross-sectional view showing an example of an organicelectronic device according to a ninth embodiment of the presentinvention.

FIGS. 18A and 18B are schematic diagrams showing the change in theconductivity of the organic electronic device according to the ninthembodiment, and FIG. 18A is a graph showing change in current withrespect to voltage change, and FIG. 18B is a schematic diagram showing aswitching operation depending on whether or not a voltage is applied.

FIG. 19 is an NMR chart of a pyrrolyl compound obtained in one exampleof the present invention.

FIG. 20 is an IR chart of the pyrrolyl compound.

FIG. 21 is an NMR chart of a thienyl compound obtained by anotherexample of the present invention.

FIG. 22 is an IR chart of the thienyl compound.

FIG. 23 is a schematic view for illustrating a rubbing method in oneexample of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

As described above, an organic electronic device of the presentinvention includes a substrate, at least two electrodes formed on thesubstrate, a conductive organic thin film that is formed on thesubstrate and electrically connects the electrodes, and a coating filmfor coating at least a portion of the electrodes. The conductive organicthin film is a polymer of organic molecules containing aconjugated-bondable group, and one end of each of the organic moleculesis chemically bonded to the surface of the substrate and theconjugated-bondable groups in the organic molecules are polymerized withother conjugated-bondable groups to form a conjugated bond chain. Thecoating film electrically connects the electrodes to the conductiveorganic thin film and achieves a smaller connection resistance than thatin the case where the electrodes and the conductive organic thin filmare connected directly.

According to such an organic electronic device, the coating filmelectrically connects the electrodes to the conductive organic thin filmand reduces the connection resistance, so that excellent electricalconnectivity between the electrodes and the conductive organic thin filmis achieved.

Furthermore, since the conductive organic thin film is used forelectrically connecting the electrodes, for example, even when furtherfine processing is performed to increase the density of the device, anexcellent property of independece of crystallinity is provided. In theconductive organic thin film in the organic electronic device of thepresent invention, a conjugated bond chain is formed by polymerizingorganic molecules and a conductive network is formed using thisconjugated bond chain, and thus conductivity is generated. Moreover,“conductive network” refers to an aggregate of conjugated bond chainsinvolved in electrical conduction.

Such an organic electronic device can be utilized for variousapparatuses such as liquid crystal display apparatuses,electroluminescent display apparatuses, and electroluminescence devices,and is useful.

Preferred examples of the coating film include a metal film containingat least one selected from the group consisting of gold, platinum, andsilver. These metal films have good contact with the conjugated bondchains involved in conductivity that are formed by polymerizing theorganic molecules in the conductive organic thin film. Moreover, theelectrodes can be protected from corrosion by coating the electrodeswith such a metal film. Hereinafter, the metal film for coating theelectrodes is referred to as “metal film for coating.”

In this case, it is preferable that the electrodes contain at least onemetal selected from the group consisting of Ni, Ti, indium tin oxide(ITO), Cr, and W. In particular, it is preferable that each of theelectrodes is a single Ni layer or a layered product having a Ni layeras an uppermost layer. When a Ni layer is used for the electrodes asdescribed above, the contacting property of the electrodes with thecoating film made of gold or the like is improved. “Ni layer” refers notonly to a layer containing only Ni but also a layer made of, forexample, Ni alloys. The same is true of the other layers containing ametal.

Another preferred example of the coating film is a conductive polymericfilm. Since the conductive polymeric film is organic, the conductivepolymeric film has good contact with the conjugated bond chains involvedin conductivity in the conductive organic thin film. Hereinafter, theconductive polymeric film for coating the electrodes is referred to as“polymeric film for coating.”

There is no particular limitation regarding the polymeric film forcoating, as long as it exhibits conductivity, and examples thereofinclude a conductive polymeric film based on at least one selected fromthe group consisting of polypyrrole, polythiophene, polyaniline,polyacetylene, polydiacetylene, and polyacene. Such conductive polymerscan, for example, connect to the conductive organic thin film byconjugated bonding as will be described later and therefore haveexcellent electrical connectivity.

Still another preferred example of the coating film is a monomolecularfilm that is chemically bonded to the surfaces of the electrodes. Sincethe monomolecular film is organic, the monomolecular film has goodcontact with the conjugated bond chains involved in conductivity in theconductive organic thin film. Moreover, the monomolecular film has avery small film thickness, so that a tunneling effect occurs, and forexample, even when the monomolecular film itself has no conductivity,the tunneling effect enables conduction. Hereinafter, the monomolecularfilm for coating the electrodes is referred to as “monomolecular filmfor coating.”

It is preferable that the monomolecular film for coating is amonomolecular film containing constituent molecules that are chemicallybonded to the surfaces of the electrodes by a —S— bond. The constituentmolecules are firmly fixed to the surfaces of the electrodes, so that avery thin monomolecular film having excellent durability againstexfoliation and the like can be formed.

Preferred examples of the monomolecular film for coating include amonomolecular film in which at least a part of the constituent moleculesare conjugated-bonded to the conjugated-bondable groups in the organicmolecules constituting the conductive organic thin film. Such amonomolecular film is particularly excellent in electrical connectivitywith the conductive organic thin film.

Examples of the constituent molecule of such a monomolecular filminclude a molecule selected from the group consisting of pyrrolederivatives, thiophene derivatives, aniline derivatives, acetylenederivatives, and diacetylene derivatives containing a substituent thatis bonded to the surface of the electrode by a —S— bond. It should benoted that a thiophene derivative refers to a compound having a thienylgroup and a pyrrole derivative refers to a compound having a pyrrolylgroup.

It is preferable that the pyrrole derivative is a pyrrole derivativehaving a substituent that is bonded to the surface of the electrode by a—S— bond in nitrogen (N) in position 1 of a pyrrole ring. Moreover, itis preferable that the thiophene derivative is a thiophene derivativehaving a substituent that is bonded to the surface of the electrode by a—S— bond in at least one of carbons (C) in positions 3 and 4 of athiophene ring.

Moreover, it is preferable that the constituent molecules of themonomolecular film for coating are polymerized by conjugated bonding.The reason for this is that since the monomolecular film itself isprovided with conductivity, electrical connectivity between theelectrodes and the conductive organic thin film is further improved.

Furthermore, another preferred example of the monomolecular film forcoating is a monomolecular film in which at least a part of theconstituent molecules are bonded covalently to portions other than theconjugated-bondable groups in the organic molecules constituting theconductive organic thin film. In particular, it is preferable that theconstituent molecules of the coating film and the organic moleculesconstituting the conductive organic thin film are bonded by at least oneof a siloxane bond (—SiO—) and a —SiN— bond. Such a monomolecular filmforms a particularly firm chemical bond with the conductive organic thinfilm and is particularly excellent in connectivity.

Moreover, when a monomolecular film is used as the coating film, it ispreferable to orient the constituent molecules of the monomolecularfilm. Orienting refers to tilting the constituent molecules in apredetermined direction.

When a conductive polymeric film and a monomolecular film are used asthe coating film, it is preferable that at least surface portions of theelectrodes contain at least one metal selected from the group consistingof gold, platinum, and silver. The reason for this is that when thesurface portions of the electrodes contain such a metal, the insides ofthe electrodes can be prevented from being corroded. Moreover, thesurfaces of the electrodes made of such a metal easily can be bonded tothe constituent molecules via the thiol groups when forming amonomolecular film for coating as described above.

In particular, it is preferable that each of the electrodes has astructure constituted by an inner layer formed on the substrate and anouter layer for coating the inner layer and this outer layer is a layercontaining at least one metal selected from the group consisting ofgold, platinum, and silver. As the inner layer, for example, a layercontaining at least one metal selected from the group consisting of Ni,Ti, indium tin oxide (ITO), Cr, and W can be used, and it isparticularly preferable that the inner layer is a single Ni layer or alayered product having a Ni layer as an uppermost layer. When Ni is usedfor the inner layer as described above, the inner layer also has goodcontact with the outer layer made of gold or the like.

Moreover, in the organic electronic device, it is preferable that theconductive organic thin film is a monomolecular film or a monomolecularbuilt-up film. Such a conductive organic thin film advantageouslyexhibits extremely good conductivity even when the film thickness issmall. Furthermore, in the case of the monomolecular built-up film, adesired conductivity can be achieved by changing the number ofmonolayers. The conductivity of the monomolecular built-up film dependson, for example, the number of layers of monomolecules that are layered,and for example, when the same monomolecular films are built up,conductivity is almost proportional to the number of the built-upmonomolecular films.

Moreover, it is preferable that the chemical bond between the conductiveorganic thin film and the substrate is at least one bond selected from asiloxane bond (—SiO—) and a —SiN— bond. In this case, Si and N may bebonded to other bonding groups corresponding to respective valences. Anexample of the form in which other bonding groups are bonded is a formin which end-bonding groups of the organic molecules are bonded to eachother and thus the organic molecules are polymerized.

Moreover, the conductive organic thin film has a conjugated bond chainpolymerized by conjugated bonding of the organic molecules, and theconjugated bond chain is preferably a chain of at least one selectedfrom the group consisting of polypyrrole, polythiophene, polyacetylene,polydiacetylene, polyacene, polyphenylene, polyphenylenevinylene,polypyridinopyridine, and polyaniline, and derivatives thereof, andamong these, polypyrrole, polythiophene, polyacetylene, polydiacetylene,and polyacene are more preferable, and polypyrrole and polythiophene areparticularly preferable. Furthermore, examples of the derivative ofpolyacetylene include polymethylacetylene, polybutylacetylene,polycyanoacetylene, polydicyanoacetylene, polypyridylacetylene, andpolyphenylacetylene.

Moreover, the organic electronic device in the present invention is notlimited to a particular type, but, for example, a three-terminal organicelectronic device and a two-terminal organic electronic device arepreferable.

In the case of the three-terminal organic electronic device, it ispreferable that the organic molecule constituting the conductive organicthin film contains a polar functional group containing no activehydrogen between the conjugated-bondable group and a site that ischemically bonded to the surface of the substrate. In the conductiveorganic thin film constituted by the organic molecules having a polarfunctional group as described above, sensitivity to an applied voltageis further increased, so that the conductivity can be changed at a highspeed. Therefore, with such a conductive organic thin film, an excellentdevice having a high response speed is obtained. It is believed thatsuch a change in the conductivity was caused by the fact that thestructure of the conductive network was influenced by the electric fieldresponse of the polar functional group.

Examples of the polar functional group include at least one groupselected from the group consisting of an ester group (—COO—), anoxycarbonyl group (—OCO—), a carbonyl group (—CO—), and a carbonate(—OCOO—) group. With a functional group in which polarization increasesby application of an electric field as described above, sensitivity tothe applied electric field becomes very high and also the response speedbecomes very high.

It is possible that the three-terminal organic electronic device has astructure in which a third electrode for applying an electric field tothe conductive organic thin film is provided in addition to the twoelectrodes (the first electrode and the second electrode). Moreover, forexample, a configuration in which the substrate is a silicon substrateand the conductive organic thin film is provided on the substrate via afilm containing an oxide, and the substrate functions as the electrodefor controlling the electric field that acts on the conductive organicthin film by applying a voltage between the two electrodes is alsopossible.

On the other hand, in the case of the two-terminal organic electronicdevice, it is preferable that the organic molecule contains aphotoresponsive functional group between the conjugated-bondable groupand a site that is chemically bonded to the surfaces of the coatingfilms or the surface of the substrate. An example of the photoresponsivefunctional group is an azo group (—N═N—). In the conductive organic thinfilm constituted by the organic molecules having a photoresponsive groupas described above, for example, sensitivity to light is improved, sothat the conductivity can be changed at a high speed by irradiation withlight. Therefore, with such a conductive organic thin film, an excellentdevice having a high response speed is obtained, and thus the device canbe used for, for example, variable resistances, switching devices,optical sensor devices, and memory devices. It is believed that such achange in the conductivity was caused by the fact that thephotoresponsive functional group produced a response to light with whichit was irradiated and the structure of the conductive network wasinfluenced by this response.

Photoresponsivity refers to a characteristic that the state of amolecule is changed reversibly by irradiation with light, andphotoresponse includes photoisomerization, a typical example of which iscis-trans isomerization, and the like by which the order (sequence) inwhich atoms constituting the molecule are bonded remains unchanged butspatial arrangement thereof is changed. Therefore, the change in theconductivity of the conductive organic thin film is reversible and theconductivity can be restored to a predetermined state by combinedirradiation with light having different wavelengths and the like.

Furthermore, in the organic electronic device, it is preferable that theorganic molecules constituting the conductive organic thin film areoriented. The conductive organic film can be provided with highconductivity by orienting the organic molecules. Moreover, theconjugated bond chains constituting the conductive network can bearranged almost parallel to each other in a particular plane in theconductive organic thin film by orienting the organic molecules. Thus, adirectional conductive network can be formed, and the conductive organicthin film also can be provided with conduction anisotropy.

Orienting refers to tilting each of the organic molecules constitutingthe organic thin film in a predetermined direction. Moreover, in thepresent invention, orientation direction of the organic molecules refersto the direction of a line segment on which major axes of the organicmolecules are projected.

Furthermore, in the organic electronic device, there is no particularlimitation regarding a material of the substrate, but, for example,known insulative materials such as glass and quartz are preferable. Thereason for this is that a glass substrate, a quartz substrate and thelike can easily form a covalent bond with an end of each of the organicmolecules constituting the conductive organic thin film and have gooddurability against exfoliation and the like and also have good contactwith the metal electrodes formed on the substrate because the surfacesof these substrates are hydrophilic and have active hydrogen. Moreover,when the substrate is made of an insulative material, for example, thesubstrate itself is never charged, and thus leakage current is small andan organic electronic device having excellent operating stability can beprovided.

Moreover, another preferred example of the substrate is a plasticsubstrate such as polyethersulfone, polyethylene terephthalate, epoxyresin, and acrylic resin. These substrates have flexibility, so that anorganic electronic device using such a substrate has wide applicability.

Furthermore, in the present invention, the surface of the substrate maybe coated with an oxide film. When the substrate is coated with an oxidefilm, the type of the substrate is not limited to the insulativesubstrates as described above. The reason for this is that when an oxidefilm is formed on the surface of the substrate, this film serves as aninsulating film. Moreover, such an oxide film easily can form a covalentbond with an end of each of the organic molecules constituting theconductive organic thin film and has good durability against exfoliationand the like because the surface of the oxide film is hydrophilic andhas active hydrogen. Therefore, when an oxide film is formed on thesurface of the substrate, it is sufficient that each of the organicmolecules is covalently bonded to the surface of the oxide film in placeof the surface of the substrate.

Examples of the oxide film include inorganic oxides such as SiO₂, Al₂O₃,Y₂O₃, ZrO₂, Ta₂O₅, La₂O₃, Nb₂O₃, and TiO₂, and among these, SiO₂, ZrO₂,Ta₂O₅, and La₂O₃ are preferable. Moreover, the oxide film may be, forexample, a complex oxide such as barium zirconate titanate (BZT) andbarium strontium titanate (BST), or may be an amorphous metal oxidefilm. It is also possible to use, for example, an organic oxide such aspolyvinyl phenol. Moreover, the oxide film may contain one type of oxideor two or more types of oxides.

A method for manufacturing the organic electronic device of the presentinvention includes, as described above, forming at least two electrodeson a substrate having active hydrogen on its surface, forming a coatingfilm on the surfaces of the electrodes, forming a precursor of aconductive organic thin film on the surface of the substrate such thatat least a portion of the precursor is in contact with the coating filmby bringing organic molecules containing a conjugated-bondable groupthat can be polymerized with other molecules and an end-bondable groupthat can be chemically bonded to the surface of the substrate in one endinto contact with the surface of the substrate to form a chemical bondby a reaction between the active hydrogen on the surface of thesubstrate and the end-bondable group, and forming the conductive organicthin film by polymerizing the conjugated-bondable groups in the organicmolecules constituting the precursor of the conductive organic thin filmwith other conjugated-bondable groups to form a conjugated bond chain toconnect the electrodes electrically via the conductive organic thinfilm.

With such a manufacturing method, the organic electronic device of thepresent invention as described above can be manufactured.

When forming a metal film containing, for example, gold, platinum, andsilver as the coating film, plating using substitution can be performedas a formation method thereof

Moreover, when forming a conductive polymeric film as the coating film,electrolytic polymerization using the electrodes formed on the substrateas electrolytic electrodes can be employed as a formation method thereofMore specifically, for example, a method of immersing the substrateprovided with the electrodes in a solution containing organic moleculescontaining at least one group selected from the group consisting of apyrrolyl group, a thienyl group, an ethynylene group (—C≡C—), and adiacetylene group (—C≡C—C≡C—), and electrolyzing the solution using theelectrodes as the electrolytic electrodes can be employed.

Furthermore, when forming a monomolecular film as the coating film, themonomolecular film can be formed by contacting organic moleculescontaining a reactive group that can be chemically bonded to thesurfaces of the electrodes in one end and a group that can form aconjugated bond with the organic molecule constituting the precursor ofthe conductive organic thin film in the other end to form a chemicalbond by a reaction between the reactive group and the electrodes.

In this case, in the step of forming the conductive organic thin film,the organic molecules constituting the precursor of the conductiveorganic thin film can be conjugated-bonded to each other, and also theorganic molecules constituting the precursor of the conductive organicthin film can be conjugated-bonded to the organic molecules constitutingthe coating film.

Examples of the group that can form a conjugated bond with the organicmolecule constituting the precursor of the conductive organic thin filminclude at least one group selected from the group consisting of apyrrolyl group, a thienyl group, an ethynylene group (—C≡C—), and adiacetylene group (—C≡C—C≡C—).

Moreover, when forming a monomolecular film as the coating film, it isalso possible to employ a method of contacting organic moleculescontaining a reactive group that can be chemically bonded to thesurfaces of the electrodes at one end and a group having active hydrogenat the other end to form a chemical bond by a reaction between thereactive group and the electrodes as a formation method.

In this case, in the step of forming the precursor of the conductiveorganic thin film, a chemical bond can be formed by a reaction betweenreactive groups in the organic molecules constituting the precursor ofthe conductive organic thin film and groups containing active hydrogenin the organic molecules constituting the coating film.

Examples of the group having active hydrogen include at least one groupselected from the group consisting of an —OH group, a —COOH group, a—NH₂ group, and a —NH group.

Furthermore, when forming a monomolecular film as the coating film, itis also possible to employ a method of forming a precursor of thecoating film on the surfaces of the electrodes by contacting organicmolecules containing a reactive group that can be chemically bonded tothe surfaces of the electrodes in one end and a group that can beprovided with active hydrogen in the other end to form a chemical bondby a reaction between the reactive group and the electrodes, and thenperforming a treatment for providing active hydrogen to the precursor ofthe coating film as a formation method.

Also in this case, in the step of forming the precursor of theconductive organic thin film, a chemical bond can be formed by areaction between reactive groups in the organic molecules constitutingthe precursor of the conductive organic thin film and groups containingactive hydrogen in the organic molecules constituting the coating film.

The group that can be provided with active hydrogen refers to a groupthat can be changed into a group having active hydrogen as describedabove by performing an appropriate treatment after a film is formed.Examples thereof include a group containing at least one group selectedfrom the group consisting of an unsaturated hydrocarbon group (in thiscase, active hydrogen is provided by oxidation) and an ester group (inthis case, active hydrogen is provided by hydrolysis).

Moreover, examples of the treatment for providing active hydrogeninclude a treatment of oxidizing or hydrolyzing the group that can beprovided with active hydrogen in the organic molecule constituting theprecursor of the coating film. For example, when the group that can beprovided with active hydrogen contains an unsaturated group, an —OHgroup and the like can be introduced by oxidizing this group.Alternatively, when the group that can be provided with active hydrogencontains an ester group, an —OH group and the like can be introduced byhydrolyzing this group.

In all of the above-described methods, an example of the reactive groupthat can be chemically bonded to the surfaces of the electrodes is amercapto (—SH) group. When the reactive group is a mercapto group, a —S—bond is formed as the chemical bond between the surface of the electrodeand the coating film.

In the manufacturing method, it is preferable that at least surfaceportions of the electrodes contain at least one metal selected from thegroup consisting of gold, platinum, and silver.

In the manufacturing method, it is preferable that the precursor of theconductive organic thin film is a monomolecular film or a monomolecularbuilt-up film. According to this preferred example, a conductive organicthin film in the form of a monomolecular film or in the form of amonomolecular built-up film can be formed.

In the manufacturing method, the organic molecules for forming theprecursor of the conductive organic thin film contain an end-bondablegroup and a conjugated-bondable group.

It is preferable that the conjugated-bondable group is a functionalgroup containing at least one group selected from the group consistingof a pyrrolyl group, a thienyl group, an ethynylene group (—C≡C—), and adiacetylene group (—C≡C—C≡C—). When the conjugated-bondable groupcontains a pyrrolyl group, a polypyrrole-based conjugated bond chain canbe formed, and when containing a thienyl group, a polythiophene-basedconjugated bond chain can be formed. Moreover, when theconjugated-bondable group contains an ethynylene group, apolyacetylene-based conjugated bond chain can be formed, and whencontaining a diacetylene group, a polydiacetylene- or a polyacene-basedconjugated bond chain can be formed.

It is preferable that the end-bondable group is a silyl halide group, analkoxysilyl group, or an isocyanate silyl group. It is preferable thatthe silyl halide group is, in particular, a chlorosilyl group. Moreover,it is preferable that the alkoxysilyl group is, in particular, analkoxysilyl group having 1 to 3 carbon atoms.

When the end-bondable group is a silyl halide group, a covalent bond canbe formed by a dehydrohalogenation reaction with active hydrogen on thesurface of the substrate. When the end-bondable group is an alkoxysilylgroup, a covalent bond can be formed by a dealcoholization reaction withactive hydrogen on the surface of the substrate. Moreover, when theend-bondable group is an isocyanate silyl group, a covalent bond can beformed by a reaction for removing isocyanate groups with active hydrogenon the surface of the substrate.

Furthermore, it is preferable that the organic molecules for forming theprecursor of the conductive organic thin film contain a polar functionalgroup containing no active hydrogen between the end-bondable group andthe conjugated-bondable group. According to this preferred example,molecules freely rotate easily in the polar functional group portion,and thus there is an advantage that the organic molecules constitutingthe organic thin film are oriented easily. Examples of the polarfunctional group include at least one group selected from the groupconsisting of an ester group (—COO—), an oxycarbonyl group (—OCO—), acarbonyl group (—CO—), and a carbonate (—OCOO—) group.

Moreover, it is preferable that the organic molecules for forming theprecursor of the conductive organic thin film contain a photoresponsivefunctional group between the end-bondable group and theconjugated-bondable group. An example of the the photoresponsivefunctional group is an azo group (—N═N—).

In the manufacturing method, it is preferable that polymerization isperformed by at least one polymerization method selected fromelectrolytic polymerization, catalytic polymerization, and energy beamirradiation polymerization.

Furthermore, in the manufacturing method, it is preferable to orient theorganic molecules constituting the precursor of the conductive organicthin film. The conjugated-bondable groups can be arranged in a certaindirection and also the conjugated-bondable groups can be arranged inclose proximity to each other by orienting the organic molecules.Consequently, polymerization of the organic molecules can proceed easilyand a conducting region with high conductivity can be formed.

Examples of the orientation method include rubbing, a treatment ofdraining liquid from the surface of the substrate provided with thecoating film in a predetermined direction, and polarized lightirradiation. Moreover, the organic molecules constituting the coatingfilm also can be oriented using fluctuation of molecules during thepolymerization.

Next, preferred examples of the conductive organic thin filmconstituting the organic electronic device of the present invention willbe described in further detail. This conductive organic thin film is apolymer of organic molecules and a conjugated bond chain is formed bypolymerization of the organic molecules. A conductive network is formedby such a conjugated bond chain, and thus conductivity is provided.

In the conductive organic thin film, the conductive network ispreferably directional. In this case, the direction of the conductivenetwork preferably is matched with the direction of the connectionbetween the electrodes. It should be noted that even when the conductivenetwork is directional, the conjugated bond chains constituting theconductive network are not required to lie in strictly one direction.For example, it is sufficient that although the conductive networkincludes the conjugated bond chains that lie in various directions, theconductive network as a whole is formed to be in a particular direction(i.e., the direction of the connection between the electrodes).

Moreover, the conductivity (ρ) of the conductive organic thin film is,for example, but not limited to, 1 S/cm or more, preferably 1×10³ S/cmor more, more preferably 1×10⁴ S/cm or more, even more preferably5.5×10⁵ S/cm or more, and most preferably 1×10⁷ S/cm or more. All of theabove values are obtained at room temperature (25° C.) without a dopant.As above, the conductive organic thin film also can have a conductivitythat is equivalent to or larger than that of metals.

The conductive organic thin film can be formed, for example, by formingan organic thin film (hereinafter, referred to as “precursor thin film”)constituted by organic molecules having a conjugated-bondable group andthen polymerizing the conjugated-bondable groups in the organicmolecules.

As the organic molecule that serves as a material of the precursor thinfilm, one containing an end-bondable group in one end of a molecule andcontaining a conjugated-bondable group in any portion of the molecule isused, as described above.

The conjugated-bondable group is a functional group that can form aconjugated bond by polymerization with other molecules. With theconjugated bond chain formed by this polymerization, the conductivenetwork is formed as described above, and thus the conductivity of theorganic conductive thin film is generated. Specific examples of theconjugated-bondable group are as described above.

The end-bondable group is a functional group that can react with thesurface of the substrate and form a chemical bond, preferably a covalentbond. Reacting with the surface of the substrate and forming a bondrefers not only to bonding directly with the surface of the substratebut also, for example, bonding with the surface of an insulating film inthe case where the insulating film is formed on the surface of thesubstrate. Specific examples of the end-bondable group are as describedabove.

Furthermore, the organic molecule preferably has the polar functionalgroup or the photoresponsive functional group containing no activehydrogen between the conjugated-bondable group and the end-bondablegroup. Specific examples of the polar functional group and thephotoresponsive functional group are as described above.

Preferred examples of the organic molecule include a compound expressedby chemical formula (5) or (6) below.

In the above formulae, X is hydrogen, an organic group containing anester group, or an organic group containing an unsaturated group. q isan integer of 0 to 10, Z is an ester group (—COO—), an oxycarbonyl group(—OCO—), a carbonyl group (—CO—), or a carbonate group (—OCOO—), D ishalogen, an isocyanate group, or an alkoxyl group having 1 to 3 carbonatoms, E is hydrogen or an alkyl group having 1 to 3 carbon atoms, m andn are integers satisfying 2≦(m+n)≦25, preferably 10≦(m+n)≦20, and p isan integer of 1 to 3.

When X is an organic group containing an ester group, examples thereofinclude a linear hydrocarbon group or a linear hydrocarbon groupcontaining an unsaturated hydrocarbon group, and X has, for example, 1to 10 carbon atoms, and preferably 1 to 6 carbon atoms. Specificexamples of X include CH₃COO—, C₂H₅—COO—, and C₃H₇—COO—.

When X is an organic group containing an unsaturated group, examplesthereof include a chain unsaturated hydrocarbon and a cyclic hydrocarbonsuch as an alicyclic hydrocarbon and an unsubstituted aromatichydrocarbon. These may be substituted with a substituent or may not besubstituted, and may be linear or branched. Examples of the unsaturatedhydrocarbon include an alkenyl group such as CH₂═CH— and CH₃—CH═CH— andan alkynyl group, and the number of carbon atoms thereof is, forexample, preferably in the range of 2 to 10, more preferably in therange of 2 to 7, and particularly preferably in the range of 2 to 3.Examples of the alicyclic hydrocarbon include a cycloalkenyl group.Moreover, examples of the aromatic hydrocarbon include an aryl group andan arylene group.

Specific examples of the chemical formula (5) include a compound (PEN:6-pyrrolylhexyl-12,12,12-trichloro-12-siladodecanoate) expressed bychemical formula (9) below and a compound(8-pyrrolyloctyl-8,8,8-trichloro-8-silaoctanoate) expressed by chemicalformula (10) below.

Furthermore, specific examples of the chemical formula (6) include acompound (TEN: 6-(3-thienyl)hexyl-12,12,12-trichloro-12-siladodecanoate)expressed by chemical formula (11) below and a compound(8-(3-thienyl)octyl-8,8,8-trichloro-8-silaoctanoate) expressed bychemical formula (12) below.

When the organic molecules shown in the formula (5) or (6) arepolymerized, a conductive organic thin film constituted by units shownin chemical formula (1) or (2) below, respectively, is formed. In theformulae (1) and (2), X, Z, E, q, m, n and p are the same as those inthe formulae (5) and (6).

In addition to these, examples of the organic molecule include anorganic molecule having the polar functional group that can be expressedby the following chemical formulae. In both of the following formulae,X, D, E, p, m and n are the same as those in the formulae (5) and (6).(CH₃)₃Si—C≡C—(CH₂)_(m)—OCO—(CH₂)_(n)—SiD_(p)E_(3-p)  (13)X—(CH₂)_(q)—C≡C—C≡C—(CH₂)_(m)—OCO—(CH₂)_(n)—SiD_(p)E_(3-p)  (14)

When the organic molecules shown in the formulae (13) and (14) arepolymerized, conductive organic thin films constituted by units shown informulae (15) and (16) below, respectively, are formed. In both of thefollowing formulae, X, D, E, p, m and n are the same as those in theformulae (13) and (14).

Moreover, it is also preferable that the organic molecule has aphotoresponsive functional group containing no active hydrogen, andspecific examples of such an organic molecule include substances asshown below. It should be noted that the organic molecule is not limitedto these substances.

In the chemical formulae (7) and (8), X, D, E and p are the same asabove, and each s and t is an integer of 1 to 20.

Specific examples of the chemical formulae (7) and (8) include compoundsexpressed by chemical formulae (17) and (18) below.

When the organic molecules shown in the formula (7) or (8) arepolymerized, a conductive organic thin film constituted by units shownin chemical formula (3) or (4) below, respectively, is formed. In thechemical formulae (3) and (4), X, E, q, s and t are the same as those inthe formulae (7) and (8).

Furthermore, in addition to these, examples of the organic moleculeinclude organic molecules expressed by chemical formulae (19) and (20)below. In the following formulae, X, D, E, p, s and t are the same asthose in the formulae (15) and (16).(CH₃)₃Si—C≡C—(CH₂)_(s)—N═N—(CH₂)_(t)—SiD_(p)E_(3-p)  (19)X—(CH₂)_(q)—C≡C—C≡C—(CH₂)_(s)—N═N—(CH₂)_(t)—SiD_(p)E_(3-p)  (20)

When the organic molecules shown in the formulae (19) and (20) arepolymerized, conductive organic thin films constituted by units shown informulae (21) and (22) below, respectively, are formed. In both of thefollowing formulae, X, D, E, p, s and t are the same as those in theformulae (19) and (20).

Moreover, examples of the organic molecule having neither polarfunctional group nor photoresponsive functional group as described aboveinclude, but are not limited to, substances as shown below.

In the formulae (23) and (24), X, D, E, q and p are the same as those inthe formulae (5) and (6), and r is an integer of 2 or more and 25 orless.

Next, preferred embodiments of the organic electronic device of thepresent invention will be described by way of examples.

FIRST EMBODIMENT

In this embodiment, a form in which a metal film is used as a coatingfilm will be described. FIG. 1 is a schematic cross-sectional viewshowing an example of a two-terminal organic electronic device accordingto this embodiment.

As shown in FIG. 1, in this organic electronic device 1, an insulatingfilm 3 is formed on a substrate 2, and a first electrode 4 a and asecond electrode 4 b are formed on this insulating film 3 so as to bespaced from each other. Moreover, the first electrode 4 a and the secondelectrode 4 b are coated with a metal film for coating 6. Furthermore,on the substrate 2, a conductive organic thin film 8 is formed on thesubstrate 2 via an insulating film 5 so as to coat a region between theelectrodes on the substrate 2. As shown in FIG. 1, the conductiveorganic thin film 8 is in contact with the electrodes 4 a and 4 b viathe metal film for coating 6. Moreover, on a region of the substrate 2where the electrodes 4 a and 4 b and the conductive organic thin film 8are not formed, an insulative organic thin film 7 is formed via theinsulating film 5.

FIG. 1 illustrates a side contact structure in which the side faces ofthe electrodes are in contact with the conductive organic thin film viathe metal films for coating, but the present invention is not limited tosuch a structure, and for example, a top contact structure in which thetop faces of the electrodes are in contact with the conductive organicthin film via the metal films for coating is also possible.

This organic electronic device can be manufactured, for example, in thefollowing manner. FIGS. 2A through 2G are schematic cross-sectionalviews showing a manufacturing process of the organic electronic device.

First, as shown in FIG. 2A, a substrate 2 is prepared and an insulatingfilm 3 is formed on one surface thereof. Examples of the insulating film3 include inorganic oxides such as SiO₂, Al₂O₃, Y₂O₃, ZrO₂, Ta₂O₅,La₂O₃, Nb₂O₃, and TiO₂, and among these, SiO₂, ZrO₂, Ta₂O₅, and La₂O₃are particularly preferable. Moreover, for example, a complex oxide suchas barium zirconate titanate (BZT) and barium strontium titanate (BST)and an amorphous metal oxide can be used. Furthermore, for example, anorganic oxide film such as polyvinyl phenol can be used.

There is no particular limitation regarding the method for forming theinorganic oxide, and for example, it may be formed by a conventionallyknown method such as thermal oxidation, CVD (chemical vapor deposition)and sputtering. Specifically, for example, it is possible that a Sisubstrate is used as the substrate and oxidized by heat treatment toform a SiO₂ film on the surface thereof. Moreover, also there is noparticular limitation regarding the method for forming the organic oxidefilm, and for example, a method of mixing with an appropriate solventsuch as an alcohol and applying this mixture to the surface of thesubstrate by, for example, spin coating can be employed.

When the insulating film 3 as above is formed, there is no limitationregarding the type of the substrate 2, and it may be an insulativesubstrate, a semiconductor substrate or a conductive substrate.Moreover, it may be a substrate having active hydrogen or a substratedeficient in active hydrogen. As the substrate, for example, aninorganic substrate such as silicon, glass, and quartz, and a plasticsubstrate such as polyethersulfone, polyethylene terephthalate, epoxyresin, and acrylic resin can be used.

When the substrate 2 is an insulative substrate such as a glasssubstrate and a quartz substrate as described above, it is also possibleto use this substrate without forming the insulating film. With such anelectrically insulative substrate, the leakage current is small and anorganic electronic device having excellent operating stability can beprovided. Furthermore, when a substrate having active hydrogen on itssurface is used as the substrate 2, it is possible to use this substratewithout forming an insulating film 8 described later. As such asubstrate, for example, a glass substrate, a quartz substrate, and asilicon nitride substrate can be used. On the surfaces of thesesubstrates, active hydrogen is present in the form of, for example, an—OH group, a —COOH group, a —NH₂ group, or a —NH group.

Moreover, when a plastic substrate as described above is used as thesubstrate 2, this substrate has flexibility, which advantageouslybroadens the applications of the organic electronic device. In thiscase, the thickness of the substrate can be, for example, from 0.1 mm to0.3 mm.

Next, a metal thin film 4 is formed on the surface of the insulatingfilm 3 on the substrate 2 (FIG. 2(B)), and the metal thin film 4 ispatterned to form a first electrode 4 a and a second electrode 4 b (FIG.2(C)).

Examples of a metal that serves as an electrode material include Ni, Ti,Cr and W, and their alloys, and particularly Ni or Ni alloys arepreferable. When a Ni thin film is formed as the metal thin film 4,examples of a material used include Ni, Ni—P alloys, and Ni—B alloys,and among these, Ni and Ni—B alloys are preferable, and Ni is morepreferable.

As the method for forming the metal thin film 4, for example,conventionally known methods including evaporation methods such asvacuum evaporation, ion plating, CVD method, and sputtering areapplicable. Moreover, patterning can be performed by usually knownmethods including, for example, etching of the metal thin film 4 using aphotoresist, and a lift-off technique.

The thickness of the electrode is usually in the range of 100 to 1000nm, preferably in the range of 300 to 800 nm, and more preferably in therange of 400 to 500 nm.

When etching is used as a patterning method at the time of forming theelectrodes, in addition to the electrode material, the insulating film 3present under the electrode material also may be etched. In such a case,the insulating film 5 is formed again on the substrate 2 as shown inFIG. 2(D). As the insulating film 5, one having active hydrogen on itssurface preferably is used. As such an insulating film 5, oxides asdescribed above can be used. On the surfaces of these oxides, activehydrogen is present in the form of, for example, an —OH group or a —COOHgroup.

The insulating film 5 can be formed, for example, in the same manner asdescribed above, and for example, when the substrate is a Si substrate,a very thin natural oxide film (SiO₂) is formed on the surface of thesubstrate by washing, and this film can be used as the insulating film5. For improving amplifying characteristics of the organic electronicdevice, for example, it is desirable to reduce the thickness of theinsulating film, so that the natural oxide film as described above isparticularly preferable because the thickness thereof is usually assmall as 0.3 to 10 nm. When the substrate is an insulative substrate,the process can proceed to the next step without forming the insulatingfilm.

Then, as shown in FIG. 2E, the electrodes 4 a and 4 b are coated with ametal film for coating 6. Examples of the metal film for coating 6include Au, Pt, and Ag.

There is no particular limitation regarding the method for coating withthe metal film for coating 6, and examples thereof include known methodssuch as electroless gold plating using substitution or catalyticreduction, and electrolytic plating. Hereinafter, the coating methodwill be described, taking the case where the electrodes 4 a and 4 b areNi layers and the metal film for coating is Au as an example. It shouldbe noted that also in the case where the metal film for coating is Pt,the same method can be employed.

(1) Substitution-Type Gold Plating

Substitution-type gold plating is a method of utilizing the differencein ionization tendency between metals. In this embodiment, Ni has agreater ionization tendency than Au. Therefore, when Ni layers(electrodes) that are the objects to be plated are immersed in asolution containing Au ions, Ni on the surfaces of the Ni layers aredeprived of electrons (oxidized) by the Au ions in the solution anddissolved in the form of Ni ions, whereas the Au ions receive theelectrons and are precipitated on the surfaces of the Ni layers, andthus gold plating is achieved.

Substitution-type gold plating can be performed, for example, by using acommercially available substitution gold plating bath, according to theusage method thereof. Usually, gold contained in the plating bath ispotassium gold cyanide or the like and the solvent is pure water.Specifically, for example, commercially available plating baths havingproduct names of Aurolectroless SMT-301 and Aurolectroless SMT-210(manufactured by Meltex Inc.) can be used.

There is no particular limitation regarding the conditions forsubstitution-type gold plating, but it is preferable to grow the Aulayers until the Ni layers on the substrate are completely coated.Specifically, for example, when substitution-type gold plating isperformed at a reaction temperature of 80 to 90° C., plating with Au canbe performed at a rate of 0.01 to 0.1 μm per minute in thickness.

As long as the Au layers completely coat the Ni layers as describedabove, there is no limitation regarding the thicknesses thereof, and forexample, the thicknesses are in the range of 0.5 to 2 μm, preferably inthe range of 0.7 to 1 μm. Moreover, when substitution-type gold platingis performed as above, the thicknesses of the Ni layers are preferablyset in the range of 0.3 to 1 μm, more preferably in the range of 0.4 to0.7 μm, and particularly preferably in the range of 0.5 to 0.6 μmbecause Ni is eluted.

(2) Electrolytic Plating

The electrolytic plating is a method of precipitating a metal from ametal salt solution on the surface of a cathode by an electrolyticreaction. In this embodiment, for example, Ni layers (electrodes) formedon the substrate, which are taken as cathodes, and a platinum electrode,which is taken as an anode, are immersed in an aqueous solution of ametal salt (e.g., potassium gold cyanide) of Au to cause an electrolyticreaction. Then, Au is precipitated on the surfaces of the Ni layers andthus gold plating is achieved.

Next, as shown in FIG. 2F, an organic thin film 7 (hereinafter, referredto as “precursor thin film”) that serves as a precursor of a conductiveorganic thin film is formed on the surface of the insulating film 5 onthe substrate 2. This precursor thin film may be a monomolecular film ora monomolecular built-up film in which the monomolecular films arelayered.

FIG. 3 is a schematic diagram showing an example of the precursor thinfilm 7 constituted by a monomolecular film. In Example of FIG. 3,numeral 14 denotes an organic molecule constituting the precursor thinfilm and this organic molecule 14 has a conjugated-bondable group 11, apolar or a photoresponsive functional group 12, and an end-bondablegroup 13. As shown in the drawing, the end-bondable groups 13 are bondedto the surface of the insulating film 5 on the substrate 2, whereby theorganic molecules 14 form the monomolecular film.

When the precursor thin film 7 is a monomolecular film, the filmthickness is, for example, in the range of 1 to 2 nm. Moreover, when theorganic thin film 7 is a monomolecular built-up film, the film thicknessis, for example, in the range of 1 to 50 nm, preferably in the range of1 to 10 nm, and particularly preferably in the range of 1 to 6 nm.Furthermore, the number of the monomolecular films that are built up is,for example, in the range of 2 to 100, preferably in the range of 2 to50, and particularly preferably in the range of 2 to 6.

This precursor thin film 7 can be formed by a common method such aschemisorption and the Langmuir-Blodgett (LB) technique as describedbelow. It should be noted that the process is not limited to thesemethods.

(1) Chemisorption

Chemisorption is a method of bringing organic molecules that serve as amaterial of the precursor thin film into contact with the surface of thesubstrate and thus making the organic molecules chemisorbed to thesurface of the substrate.

As the organic molecules that serve as material of the precursor thinfilm 7, one containing an end-bondable group in one end of a moleculeand containing a conjugated-bondable group in any portion of themolecule is used, as described above. Specific examples of this organicmolecule are as described above.

When the organic molecules are brought into contact with the surface ofthe substrate, a reaction occurs between active hydrogen on the surfaceof the substrate and the end-bondable groups in the organic molecules,and a chemical bond, preferably a conjugated bond, is formed. Thus, theorganic molecules are fixed to the surface of the substrate to form theprecursor thin film 9.

For example, when the end-bondable group is a silyl halide group, analkoxysilyl group, or an isocyanate silyl group, these groups bringabout an elimination reaction such as a dehydrohalogenation reaction, adealcoholization reaction, or a reaction for removing isocyanate groupswith active hydrogen on the surface of the substrate, and thus acovalent bond is formed. For example, when active hydrogen is present inthe form of an —OH group, a siloxane (—SiO—) bond is formed as thecovalent bond, whereas when active hydrogen is present in the form of a—NH group, a —SiN— bond is formed as the covalent bond.

In chemisorption, as the method for bringing the organic molecules intocontact with the surface of the substrate, a method of adding theorganic molecules to a solvent to prepare a chemisorption solution andbringing this solution into contact with the surface of the substrategenerally is employed. As the organic solvent, for example, a nonaqueousorganic solvent such as chloroform, xylene, toluene, and dimethylsiloxane can be used. Moreover, the concentration of the organicmolecules in the chemisorption solution is, for example, but not limitedto, 0.01 to 1 mol/L, and preferably 0.05 to 0.1 mol/L.

Moreover, the time for bringing the chemisorption solution into contactis, for example, but not limited to, 1 to 10 hours, and preferably 1 to3 hours. Furthermore, the temperature of the chemisorption solution atthis time is, for example, 10 to 80° C., and preferably 20 to 30° C.Also there is no particular limitation regarding other reactionconditions for this chemisorption, but for example, the reaction ispreferably performed under a nitrogen atmosphere and the relativehumidity is preferably in the range of 0 to 30%.

As the method for bringing the chemisorption solution into contact withthe surface of the substrate, for example, a method of immersing thesubstrate in the chemisorption solution and a method of applying thechemisorption solution to the surface of the substrate can be employed.

When forming the monomolecular built-up film, after a firstmonomolecular film is formed, the surface of the monomolecular film isfurther subjected to a hydrophilization treatment, and then anothermonomolecular film can be formed by chemisorption as described above.The monomolecular built-up film with a desired number of monomolecularfilms can be formed by repeating such hydrophilization treatment andchemisorption.

There is no limitation regarding the method for hydrophilizationtreatment, and for example, when an unsaturated group such as a vinylgroup is present on the surface of the monomolecular film, a method ofirradiating the surface of a monolayer with energy rays such as electronbeams or X-rays in an atmosphere containing moisture can be employed.With this method, an —OH group can be introduced into the surface of themonomolecular film. Alternatively, a method of immersing the surface ofthe monomolecular film in an aqueous solution of potassium permanganatealso can be used. In this case, a —COOH group can be introduced into thesurface of the monomolecular film.

Moreover, when forming the monomolecular built-up film, the second andthe following monomolecular films can be formed by Langmuir-Blodgett(LB) technique and the like. In this case, hydrophilization treatment ofthe surface of the underlying monomolecular film is not necessarilyrequired. However, it is preferable to perform a hydrophilizationtreatment because the underlying monomolecular film and themonomolecular film above can be chemically bonded and thus themonomolecular built-up film having excellent durability can be formed.

When forming the monomolecular built-up film, all of the layers may beconstituted by the same organic molecules or each of the layers may beconstituted by different types of organic molecules. Moreover, there isno particular limitation regarding the structure of the monomolecularbuilt-up film and it may be any of X-type, Y-type, and Z-typestructures.

(2) LB Technique

The organic molecules as described above that are dissolved in anorganic solvent are added to an aqueous solvent, and on this watersurface, the organic molecules are spread. At this point, the organicmolecules extend over the water surface with their hydrophilic groupside in the water and hydrophobic group side on the air side to form amonomolecular film. Then, after evaporating the organic solvent, themonomolecular film can be compressed by applying a constant surfacepressure with a barrier and can be transferred onto the insulating film5 on the substrate 2. When the precursor thin film is a monomolecularbuilt-up film, monomolecules can be built up by moving the substrate 2up and down with respect to the liquid surface while applying a constantsurface pressure to the monomolecules on the water surface. When movingthe substrate up and down, if the monomolecular films are built up onlyat the time of moving down, an X-type film can be produced, if they arebuilt up only at the time of moving up, a Z-type film can be produced,and if they are built up at every stage of moving up and down, a Y-typefilm can be produced. The conditions for this LB technique are notlimited to particular conditions and can be set by a conventionallyknown method.

After forming the precursor thin film, it is preferable to wash thesurface of the substrate. By carrying out this washing process,unadsorbed organic molecules can be removed from the surface of thesubstrate, and a coating film whose surface is free from dirt can beprovided. As an organic solvent for washing the substrate, for example,chloroform, acetone, methanol, and ethanol can be used.

Then, a conductive organic thin film 8 is formed by polymerizing theorganic molecules constituting the precursor thin film 7 (FIG. 2G). Withthis conductive organic thin film 8, the first electrode 4 a and thesecond electrode 4 b are electrically connected.

In this process, “polymerization” refers to a reaction in which theconjugated-bondable groups are bonded to form a conjugated bond chain.For example, when the organic molecules constituting the coating filmalready have been polymerized at sites other than theconjugated-bondable groups, the conjugated-bondable groups within themolecules (polymers) are bonded and crosslinked, and the polymerizationin this process includes such crosslinking.

FIG. 4 is a schematic diagram showing an example of a structure of thethin film after polymerization (i.e., the conductive organic thin film8). This drawing shows the conductive organic thin film 8 obtained bypolymerizing the precursor thin film 7 shown in FIG. 3. As shown in thedrawing, the conjugated-bondable groups 11 in the organic molecules arebonded by polymerization to form a conjugated bond chain 15. Then, bythe formation of this conjugated bond chain 15, a conductive network isformed and thus the thin film is provided with conductivity.

This polymerization process can be carried out by electrolyticpolymerization. Specifically, the process can be carried out by applyinga voltage between the first electrode 4 a and the second electrode 4 b,as shown in FIG. 2G. In this case, polymerization of the organicmolecules is achieved by electrochemical oxidation or reduction of theconjugated-bondable groups therein, so that the process proceeds only ina region between the first electrode 4 a and the second electrode 4 bwhere an electric field is applied. Therefore, with this electrolyticpolymerization, the conductive network can be formed between the firstelectrode 4 a and the second electrode 4 b in a self-alignment manner.On the other hand, in a region other than the region between the twoelectrodes, the precursor thin film 7 is not polymerized, so that itremains while maintaining the insulating property.

When performing electrolytic polymerization in this manner, usually,generation of hydrogen or oxygen disadvantageously causes corrosion ofthe metal electrodes, but the electrodes in the organic electronicdevice of the present invention can be prevented from being corrodedduring polymerization because they are coated with the Au layers asdescribed above.

The magnitude of the voltage applied between the electrodes can be setin accordance with the oxidation-reduction potential of the organicmolecules constituting the precursor thin film 7. The applied voltage isset in such a manner that the strength of the electric field generatedbetween the two electrodes becomes, for example, in the range of 5 to500 v/cm, preferably 100 to 300 v/cm, and particularly preferably in therange of 100 to 150 v/cm. The strength of the electric field that isoutside these ranges can be used by, for example, adjusting theapplication time and the like.

As the voltage applied between the electrodes, both direct voltage andalternating voltage can be used. Moreover, the voltage applied betweenthe electrodes also can be a pulse wave. Usually, electrolytic oxidationpolymerization generates hydrogen, and when hydrogen is generatedlocally, the generated hydrogen becomes a bubble and may peel off theelectrodes. It is preferable to use alternating voltage as the voltagebecause it can suppress such local generation of hydrogen. When usingdirect voltage, it is preferable to apply this in the form of pulsewaves. Voltage conditions for preventing such local generation ofhydrogen can be determined as appropriate in accordance with, forexample, the strength of the electric field and the size of theprecursor thin film to be subjected to electrolytic polymerization.

There is no particular limitation regarding the polymerization time andit is set to a time required to form the conductive network between theelectrodes. In this electrolytic polymerization process, the coatingfilm is polymerized with the electric field applied between theelectrodes, and therefore whether or not formation of the conductivenetwork is finished can be determined easily by observing whether or notcurrent flows between the electrodes. That is to say, when theconductive network has been completed, a phenomenon in which currentflows rapidly into the coating film between the electrodes can beobserved. The voltage application time is, for example, in the range of100 to 5000 minutes, preferably 100 to 600 minutes, and particularlypreferably 500 to 600 minutes.

There is no particular limitation regarding the other electrolysisconditions. For example, the electrolysis temperature can be set to from20 to 30° C., and preferably at about room temperature (25° C.).

When performing electrolytic polymerization as above, theconjugated-bondable group in the organic molecule is preferably, forexample, a pyrrolyl group or a thienylene group.

When the conductive organic thin film 8 is a monomolecular built-upfilm, formation and polymerization of each monomolecular filmconstituting the monomolecular built-up film may be performedalternately or formation of the monomolecular built-up film by layeringmonomolecules may be followed by polymerization of the entiremonomolecular built-up film.

Furthermore, a dopant may be added to the conductive organic thin film.If a charge-transfer dopant is doped, conductivity can be improved in asimple manner. As the dopant, for example, an acceptor dopant (electronacceptor) such as iodine and a BF— ion, and a donor dopant (electrondonor) such as alkali metals including Li, Na, and K and alkaline earthmetals including Ca can be used. Moreover, for example, a trace amountof components that are contained in the organic solvent for dissolvingthe organic molecules and the like or substances that are unavoidablymixed from a glass container used during formation of the precursor thinfilm 7 may be contained as a dopant substance.

Then, polymerization is finished as described above, and thus theorganic electronic device 1 of the present invention is completed.

It should be noted that the order of the polymerization process of theprecursor thin film 7 is not limited to the above-described processsequence. For example, it is also possible that the organic electronicdevice is produced in the same manner as described above except that theprecursor thin film 7 is not polymerized, and then the precursor thinfilm 7 is polymerized by applying a voltage at the time of use andchanged into the conductive organic thin film 8, whereby the organicelectronic device is completed and used as it is.

Regarding operations of this organic electronic device 1, for example,the following is an explanation of an example when the organic moleculesconstituting the conductive organic thin film have a photoresponsivefunctional group. When the photoresponsive functional group exhibitsphotoisomerization, for example, the conductivity of the conductiveorganic thin film can be changed by irradiating the conductive organicthin film with two types of light having different wavelengths. That isto say, the functional group with photoresponsivity usually has specificabsorption characteristics and is isomerized in accordance with thelight. For this reason, upon irradiation with a first light of the twotypes of light having different wavelengths, a shift to a specificconductivity is made by isomerization in accordance with this light, andupon further irradiation with a second light that is the other one,isomerization occurs again in accordance with this light to provide adifferent specific conductivity. Therefore, the conductivity can bechanged by irradiation with the two types of light, and thus currentthat flows through the conductive organic thin film can be switched.Moreover, the progress of isomerization depends on the quantity ofirradiation light, and therefore the conductivity is variably controlledby adjusting the intensity of the irradiation light, the irradiationtime, and the like, and also the range of change in the conductivity canbe adjusted. Switching also can be performed by irradiation ornon-irradiation with light.

As described above, the photoresponsive functional group has absorptioncharacteristics specific to each region in the absorption spectrum, sothat when it is irradiated with a wavelength for which absorptance isexcellent, the conductivity can be changed efficiently at a high speed.As the irradiation light, for example, ultraviolet light and visiblelight are applicable, and when the photoresponsive functional group isan azo group, for example, the conductivity can be changed by a shift toa cis-form by irradiation with visible light or a shift to a trans-formby irradiation with ultraviolet light. The wavelength of the visiblelight is preferably 400 to 700 nm, and the wavelength of the ultravioletlight is preferably 200 to 400 nm and specific examples thereof arewavelengths of 254 nm and 361 nm.

Specifically, regarding this organic electronic device, change in theconductivity of the conductive organic thin film by light irradiationwill be described with reference to FIG. 5A, and the switching operationthereof will be described with reference to FIG. 5B. In a graph in FIG.5A, the horizontal axis indicates light irradiation time and thevertical axis indicates current between the electrodes, and change inthe conductivity with respect to the irradiation time in the case wherethe conductive organic thin film is irradiated with light of a constantintensity is shown qualitatively. The change in the current is takenwhen the voltage applied between the first and the second electrodes isconstant.

As shown in the drawing, it can be seen that the current between thefirst and the second electrodes changes according to the lightirradiation time and converges on a certain value with the increase inthe light irradiation time. That is to say, this indicates the fact thatthe conductivity of the conductive organic thin film is controlled byirradiating the conductive organic thin film with light. In this manner,the conductive organic thin film is shifted between a stable state inwhich the conductivity at the time of no light irradiation is providedand a stable state in which the conductivity at the time ofpredetermined light irradiation is provided by changing the quantity ofthe irradiation light, and thus the conductivity of the conductivenetwork can be switched. The current value may become 0 A (ampere) whenthe light irradiation is performed for a sufficient length of time, oron the contrary, the current value may increase with the lightirradiation.

FIG. 5B is a conceptual diagram of the switching operation of theorganic electronic device that is performed by irradiation with thefirst light (P₁) and with the second light (P₂) having differentwavelengths in the case where the photoresponsive functional group is aphotoisomerizable functional group. Lines L1 and L2 indicate the statesduring irradiation with the first light and with the second light,respectively, (P_(1 ON), P_(2 ON)) and during shielding from theselights (P_(1 OFF), P_(2 OFF)), and a line L3 shows current I₁ duringirradiation with the first light and current I₂ during irradiation withthe second light that are responses to the irradiation states. In thesestates, the voltage is applied between the first electrode and thesecond electrode.

As shown in FIG. 5B, the current is changed according to irradiationwith the two types of light (L3), so that it can be seen that thisoperation is current switching using the first light and the secondlight as triggers and is the same operation as in a reset-set (R-S)flip-flop.

However, in FIG. 5B, only isomers caused by irradiation with the firstlight are contained in the stable state with the first conductivity, andonly the other different isomers caused by irradiation with the secondlight are contained in the stable state with the second conductivity.That is to say, the stable states with the first conductivity and withthe second conductivity are the two states that are totally isomerized.In this case, when irradiation with the first light is further performedin the first stable state, the conductivity remains unchanged, and thesame is true also when irradiation with the second light is performed inthe second stable state.

SECOND EMBODIMENT

In the above organic electronic device, a layered product containing aplurality of layers of metals or the like also can be used as theelectrode. FIG. 6 is a cross-sectional view showing an example of suchan organic electronic device, and the same members as in FIG. 1 bear thesame numerals.

This organic electronic device 20 has the same structure as in the firstembodiment except that electrodes 4 a and 4 b are layered products.Examples of the layered product constituting the electrodes 4 a and 4 binclude a layered product containing a layer made of at least one metalselected from the group consisting of Ni, Ti, indium tin oxide (ITO),Cr, and W, and particularly a Ni layer is preferable. There is noparticular limitation regarding the number of layers. FIG. 6 illustratesthe case where the electrode 4 a (4 b) is a double-layered productconsisting of a lower layer 21 a (21 b) and an upper layer 22 a (22 b)as an example, and for such a double-layered product, preferred examplesof the lower layer 21 a (21 b)/upper layer 22 a (22 b) combinationinclude Ti layer/Ni layer, ITO layer/Ni layer, Cr layer/Ni layer, and Wlayer/Ni layer, and Ti layer/Ni layer and Cr layer/Ni layer areparticularly preferable.

The method for manufacturing the above-described organic electronicdevice is the same as in the first embodiment except that metal thinfilms that are layered products are formed on the insulating film 3 onthe substrate 2 and these layered products are patterned, and thepatterned layered products serve as the electrodes.

An example where a layered product of Ti layer/Ni layer is used for theelectrodes will be described. First, Ti thin films are formed on aninsulating film 3 on a substrate 2, on top of which Ni thin filmsfurther are formed. Then, these layered products are patterned, and thepatterned layered products consisting of the Ti layers 21 a and 21 b andthe Ni layers 22 a and 22 b, respectively, serve as the electrodes 4 aand 4 b. As the method for forming the Ti layer, for example, a methodsimilar to the method for forming the Ni layer described above can beemployed. In this case, examples of material used for forming the Tilayer include Ti, Ti—Al alloys, and Ti—Sn alloys, and Ti is preferable.

When the layered product of the Ti layer and the Ni layer is coated withan Au layer by substitution-type gold plating as described above, forexample, the thickness of the Ti layer is preferably in the range of 10to 2000 nm, more preferably in the range of 20 to 1000 nm, andparticularly preferably in the range of 30 to 60 nm. The reason for thisis that with such a thickness, not only the surface of the Ni layer butalso the surface of the Ti layer that is the lower layer can besufficiently coated because of the growth of the Au layer. Specifically,for example, with the Ti layer of 50 nm and the Ni layer of 500 nm, theAu layer of about 600 to 1000 nm can be formed by electroless goldplating. When an ITO layer is provided in place of the Ti layer, theproduction process can be performed in the same manner.

THIRD EMBODIMENT

In this embodiment, a form in which a conductive polymeric film is usedas the coating film will be described. FIG. 7 is a cross-sectional viewshowing an example of such a two-terminal organic electronic device, andthe same members as in FIG. 1 bear the same numerals.

In this organic electronic device 30, an insulating film 3 is formed ona substrate 2 and a first electrode 4 a and a second electrode 4 b areformed on this insulating film 3 so as to be spaced away from each otheras in the first embodiment. In FIG. 7, a form in which the electrodes 4a and 4 b are constituted by inner layers 31 a and 31 b and outer layers32 a and 32 b with which the inner layers are coated, respectively, isshown as an example. The electrodes 4 a and 4 b are coated withpolymeric films for coating 33. Furthermore, on the substrate 2, aconductive organic thin film 8 is formed on the substrate 2 via aninsulating film 5 so as to coat a region between the electrodes on thesubstrate 2. This conductive organic thin film 8 is in contact with theelectrodes 4 a and 4 b via the polymeric films for coating 33. Inaddition, on a region of the substrate 2 where the electrodes 4 a and 4b and the conductive organic thin film 8 are not formed, an insulativeorganic thin film 7 is formed via the insulating film 5.

The organic electronic device can be manufactured, for example, in thefollowing manner. FIGS. 8A through 8H are schematic cross-sectionalviews showing a manufacturing process of the organic electronic device.

First, as in the first embodiment, the insulating film 3 is formed onthe surface of the substrate 2 (FIG. 8A). Subsequently, the electrodes 4a and 4 b are formed on the insulating film (FIGS. 8B through 8E). Asthe electrodes 4 a and 4 b, for example, but not limited to, metals suchas Ti, Ni, Au, and Pt, and their alloys can be used. It is preferablethat at least a surface portion of the electrode contains at leasteither of Au and Pt. In addition to the electrode formed of Au or Pt,examples of such an electrode include an electrode in which an innerelectrode formed of Ti, Ni, or the like is coated with an outerelectrode formed of Au, Pt, or the like.

The electrodes can be formed by forming a film with an electrodematerial on the surface of the substrate or the insulating film andpatterning this film. As the film formation method, for example,evaporation and sputtering can be employed, and as the patterningmethod, for example, etching using a resist and lift-off technique canbe employed. Moreover, as shown in the drawing, when forming theelectrodes 4 a and 4 b respectively constituted by the inner layers 31 aand 31 b and the outer layers 32 a and 32 b with which the inner layersare coated, after forming a film with the electrode material 31 (FIG.8B) and patterning this film to form the inner layers 31 a and 31 b(FIG. 8C) by the method described above, the outer layers 32 a and 32 bcan be formed on the surfaces of the inner layers 31 a and 31 b by aplating method such as electroless plating or electrolytic plating. Theplating method can be carried out in the same manner as in the processdescribed in the first embodiment.

Furthermore, the insulating film 5 is formed, if necessary. This processis the same as in the first embodiment. Moreover, when forming theelectrodes constituted by the inner layers and the outer layers as shownin the drawing, the insulating film 5 may be formed after formation ofthe inner layers 31 a and 31 b and before formation of the outer layers32 a and 32 b (FIG. 8D).

Next, as shown in FIG. 8F, the first electrode 4 a and the secondelectrode 4 b are coated with the polymeric films for coating 33.

As the polymeric film for coating 33, for example, polypyrrole-,polythiophene-, polyaniline-, polyacetylene-, polydiacetylene-, andpolyacene-based polymeric films can be used, and among these,polypyrrole- and polythiophene-based films are preferable.

Examples of monomer molecules constituting the polymeric film forcoating 33 include pyrrole, thiophene, aniline, acetylene, anddiacetylene, and derivatives thereof Examples of the acetylenederivatives include methylacetylene, butylacetylene, cyanoacetylene,dicyanoacetylene, pyridylacetylene, and phenylacetylene.

The polymeric film for coating 33 can be formed, for example, by aconventionally known method such as electrolytic polymerization orphotopolymerization in accordance with the type of the constituentmolecules (monomer molecules). The following is a description of thecase where electrolytic polymerization is employed.

For example, when forming a polypyrrole film as the polymeric film forcoating 33, the substrate 2 on which the electrodes 4 a and 4 b areformed is immersed in a solvent containing pyrrole that is theconstituent molecule, the electrodes 4 a and 4 b are immersed as anodes,and a platinum electrode is immersed as a cathode. Then, when a voltageis applied between the anodes and the cathode, pyrrole is polymerized byelectrolytic polymerization to form polypyrrole films on the surfaces ofthe anodes, that is, on the surfaces of the first and the secondelectrodes 4 a and 4 b. When forming the polypyrrole films in thismanner, pyrrole is polymerized on the anode side, so that if theelectrodes that are the anodes consist only of Ni layers, Ti layers, orAl layers, Ni may be eluted by an electrolytic reaction. For thisreason, as shown in FIG. 8E, it is preferable to coat the inner layers31 a and 31 b with the outer layers 32 a and 32 b made of gold orplatinum.

When using a pyrrole derivative, the process can be performed in thesame manner. Moreover, when forming a polythiophene film by using thiolas the constituent molecule or when using a thiophene derivative, theprocess can be performed in the same manner as well.

As the solvent containing the constituent molecule, for example, water,acetonitrile, and ethanol can be used.

This electrolytic polymerization reaction can be performed by aconventionally known method, but under the conditions that, for example,the strength of the electric field is in the range of 2 to 3 v/cm.Moreover, the voltage application time is, for example, in the range of1 to 10 minutes.

The thickness of the polymeric film for coating 33 is, for example, inthe range of 1 to 2 nm, but not limited thereto.

Next, after forming a precursor 7 (i.e., precursor thin film) of theconductive organic thin film on the surface of the insulating film 5 onthe substrate 2, the organic molecules constituting this precursor thinfilm 7 are polymerized to form the conductive organic thin film 8. Thisprocess is the same as in the first embodiment.

FOURTH EMBODIMENT

In this embodiment, a form in which a monomolecular film is used as thecoating film will be described. Such an organic electronic device hasthe same structure as in the third embodiment except that themonomolecular film is formed as the coating film in place of theconductive polymeric film, and the manufacturing method thereof is alsothe same as in the third embodiment except for the method for formingthe coating film.

In this embodiment, the monomolecular film for coating with which thesurfaces of the electrodes are coated is a monomolecular film containingan organic molecule whose end on one side is chemically bonded to thesurface of the electrode. Furthermore, it is preferable that the organicmolecules constituting this monomolecular film are conjugated-bonded tothe conductive organic thin film.

As the method for forming such a monomolecular film for coating, forexample, chemisorption can be employed. The following is a descriptionof the case where chemisorption is employed.

Chemisorption is a method of bringing organic molecules that serve asmaterial of the monomolecular film for coating into contact with thesurface of the electrode so that the organic molecules are adsorbed tothe surface of the electrode. As the organic molecules that serve asmaterial of the monomolecular film for coating, an organic moleculehaving a reactive group that can form a chemical bond with the surfaceof the substrate at one end is used.

Examples of such organic molecules include, as described above, amonomolecular film constituted by constituent molecules such as pyrrolederivatives, thiophene derivatives, aniline derivatives, acetylenederivatives, and diacetylene derivatives that are substituted with asubstituent having a thiol group at an end, and among these, pyrrolederivatives and thiophene derivatives are preferable.

The substituent having a thiol group at an end is, for example,preferably substituted with nitrogen (N) in position 1 of a pyrrole ringin the case of the pyrrole derivatives, preferably substituted withcarbon (C) in position 3 or 4 of a thiophene ring in the case of thethiophene derivatives, and preferably substituted with carbon inposition 4 of a benzene ring in the case of the aniline derivatives.

Specifically, an example of the substituent having a thiol group in anend is a group expressed by formula (A) below that contains no activehydrogen.—R¹—SH  (A)

In this formula, R¹ is, for example, but not limited to, a linear orbranched saturated hydrocarbon that is or is not substituted, a linearor branched unsaturated hydrocarbon that is or is not substituted, or—R²—Y—R³—, where Y is preferably an ester group (—COO—), an oxycarbonylgroup (—OCO—), a carbonyl group (—CO—), a carbonate (—OCOO—) group, oran azo group (—N═N—), and R² and R³ are preferably linear or branchedsaturated hydrocarbons that are or are not substituted, or linear orbranched unsaturated hydrocarbons that are or are not substituted, andR¹ has, for example, 1 to 30 carbon atoms, and preferably 10 to 25carbon atoms. Specifically, for example, a substituent such as amercaptoalkyl group or a mercaptofluoroalkyl group is preferable.

Specific examples of the derivatives include pyrrole derivatives such as1-(mercaptodecyl)pyrrole and 1-(mercaptohexadecyl)pyrrole and thiophenederivatives such as 2-(mercaptodecyl)thiophene and2-(mercaptohexadecyl)thiophene.

Regarding the combination of the conductive organic thin film and themonomolecular film for coating, for example, when the conductive organicthin film has a polypyrrole-based conjugated bond chain, for example, amonomolecular film formed of a pyrrole derivative is preferable, andwhen the conductive organic film has a polythiophene conjugated bondchain, a monomolecular film formed of a thiophene derivative ispreferable.

When the organic molecules are brought into contact with the surface ofthe electrode, a reaction occurs between the surface of the electrodeand the constituent molecules to form a chemical bond, preferably acovalent bond. For example, when the constituent molecule has a mercaptogroup (—SH), this group reacts with a metal constituting the electrodeto form a —S— bond. This chemical bond allows the organic molecules tobe fixed to the surface of the electrode, and thus the monomolecularfilm is formed.

As a specific example, FIG. 9A shows a schematic cross-sectional diagramof a state in which the surface of the electrode is coated with amonomolecular film formed of a pyrrole derivative having a mercaptoalkylgroup. As shown in the drawing, S is bonded to the surface of theelectrode 4 a, and thus a monomolecular film 41 of the pyrrolederivative is formed. In FIG. 9A, the same members as in FIG. 7 bear thesame numerals.

Regarding the method for bringing the organic molecules into contactwith the surface of the electrode, a method of preparing a chemsorptionsolution by adding the organic molecules to a solvent, and then bringingthis solution into contact with the surface of the electrode generallyis employed. As the solvent, for example, an alcohol such as ethanol andacetonitrile can be used. The concentration of the organic molecules inthe chemisorption solution is, for example, but not limited to, 0.01 to0.1 mol/L, and preferably 0.02 to 0.05 mol/L. The time for bringing thechemisorption solution into contact with the surface of the electrodeis, for example, but not limited to, 10 minutes to 3 hours, andpreferably 10 minutes to one hour. Moreover, the temperature of thechemisorption solution at this time is, for example, 10 to 35° C., andpreferably 20 to 30° C.

Regarding the method for bringing the chemisorption solution intocontact with the surface of the electrode, for example, a method ofimmersing a substrate provided with the electrodes in the chemisorptionsolution, and a method of applying the chemisorption solution to thesurfaces of the electrodes can be employed.

After forming the monomolecular film for coating, it is preferable towash the surface of the substrate. This washing process allowsunadsorbed organic molecules to be removed from the surfaces of thesubstrate and the electrodes. As an organic solvent for washing thesubstrate, for example, chloroform, acetone, methanol, and ethanol canbe used.

In this embodiment, the thickness of the monomolecular film for coatingis, for example, in the range of 1 to 2 nm. As described above, thecoating film is a monomolecular film and is very thin with a filmthickness in nanometers, so that a tunneling effect occurs, and thuseven if the coating film itself does not exhibit conductivity, currentflow from the electrode is not prevented. Therefore, at the time ofpolymerization of the precursor thin film or use of the organicelectronic device, current can be transmitted to the precursor thin filmor the conductive organic thin film.

In the coating film, it is preferable to orient the constituentmolecules. As the orientation method, for example, a method similar toan orientation treatment of the conductive organic thin film as will bedescribed in a seventh embodiment can be employed, but is not limitedthereto.

Moreover, in the monomolecular film for coating, the constituentmolecules may be polymerized by conjugated bonding. Throughpolymerization, a conductive conjugated bond chain is formed in the samemanner as in the conductive organic thin film, so that the coating filmitself exhibits conductivity, and thus electrical connectivity can beimproved even more.

Furthermore, this polymerization process also forms a conjugated bondbetween the conductive organic thin film and the coating film.

As a specific example, FIG. 9B schematically shows a monomolecular filmfor coating 42 in which a monomolecular film 41 formed of a pyrrolederivative having a mercaptoalkyl group shown in FIG. 9A is polymerized.As shown in the drawing, the constituent molecules of the monomolecularfilm are conjugated-bonded to each other in positions 2 and 5 of thepyrrole rings, and thus the polymerized monomolecular film for coating42 is formed. In FIG. 9B, the same members as in FIG. 7 bear the samenumerals.

The polymerization method can be determined as appropriate in accordancewith the type of the constituent molecules, and a method similar to thepolymerization method of the precursor thin film as described in thefirst embodiment can be applied. Moreover, this polymerization processmay be performed in advance, but in the case of the monomolecular filmformed of a pyrrole derivative or a thiophene derivative, for example,the monomolecular film may be polymerized by application of a voltage atthe time of use of the organic electronic device and then used as it is.

FIFTH EMBODIMENT

In this embodiment, another form in which a monomolecular film is usedas the coating film will be described. FIG. 10 shows an example of sucha two-terminal organic electronic device. In FIG. 10, the same membersas in FIG. 1 bear the same numerals.

This organic electronic device 50 has substantially the same structureas that in the above embodiments except that a monomolecular film isformed as the coating film, and the manufacturing method thereof is alsosubstantially the same as that in the above embodiments except for themethod for forming the coating film.

In this embodiment, monomolecular films for coating 51 for coating thesurfaces of electrodes 4 a and 4 b are monomolecular films containingorganic molecules that are chemically bonded to the surfaces of theelectrodes 4 a and 4 b at one end and are chemically bonded to theconductive organic thin film 8 at the other end.

The chemical bonds between the monomolecular films for coating 51 andthe surfaces of the electrodes 4 a and 4 b are preferably covalentbonds. An example of such a bond is a —S— bond. Moreover, the chemicalbond between the monomolecular film for coating 51 and the conductiveorganic thin film 8 is preferably a covalent bond. Examples of such abond include a —SiO— bond and a —SiN— bond. In this case, Si and N maybe bonded to other bonding groups corresponding to respective valences.Examples of the form in which other bonding groups are bonded include aform in which end-bonding groups in organic molecules are bonded to eachother and thus the organic molecules are polymerized.

FIG. 10 illustrates a top contact structure in which the top faces ofthe electrodes 4 a and 4 b are in contact with the conductive organicthin film 8, but the present invention is not limited to such astructure, and, for example, a side contact structure in which the sidefaces of the electrodes are in contact with the conductive organic thinfilm is also possible.

Such an organic electronic device 50 can be formed, for example, in thefollowing manner. FIG. 11A through 11G are views showing a processsequence for illustrating an example of the method for manufacturing theabove-described organic electronic device.

First, an insulating film 3 is formed on a substrate 2 (FIG. 11A) and afirst electrode 4 a and a second electrode 4 b are formed on thisinsulating film 3 (FIGS. 11B and 11C). Furthermore, an insulating film 5is formed, if necessary (FIG. 11D). This step can be performed in thesame manner as in the third embodiment.

Subsequently, monomolecular films that are chemically bonded to thesurfaces of the electrodes 4 a and 4 b and have active hydrogen on theirsurfaces are formed as monomolecular films for coating 51 (FIG. 11E).

FIG. 12 is a diagram showing an example of the monomolecular film forcoating 51. In an example of FIG. 12, numeral 52 denotes an organicmolecule constituting the monomolecular film for coating 51, numeral 53denotes a group that is chemically bonded to the surface of theelectrode 4 a, and numeral 54 denotes a group that contains activehydrogen. In the Example shown in FIG. 12, the groups 53 present at oneend of the organic molecules 52 are bonded to the surface of theelectrode 4 a, and thus the monomolecular film is formed. Moreover, onthe surface of the monomolecular film, the groups 54 that are present inthe other end of the organic molecules 52 and contain active hydrogenare exposed.

Regarding the method for forming such a monomolecular film for coating51, for example, chemisorption can be employed. Chemisorption can becarried out in the same manner as in the fourth embodiment except thatthe type of the organic molecules that serve as a material of themonomolecules is different.

In this embodiment, as the organic molecules that serve as the materialof the monomolecular film for coating 51, organic molecules having areactive group that can form a chemical bond with the surface of theelectrode at one end and a group that contains active hydrogen at theother end are used.

An example of such organic molecules is a compound that is expressed bychemical formula (25) below.A—R—SH  (25)

In the chemical formula, A is a group having active hydrogen. Examplesof such a group include an —OH group, a —COOH group, a —NH₂ group, and a—NH group.

Moreover, in the chemical formula, R is a saturated or unsaturatedhydrocarbon group. Examples of hydrocarbon groups include linear orbranched chain hydrocarbon groups, alicyclic hydrocarbon groups, andaromatic hydrocarbon groups, and these groups may or may not besubstituted. In particular, as a hydrocarbon group, chain hydrocarbongroups are preferable. Examples of chain hydrocarbon groups include analkylene group, an alkenylene group, and an alkynylene group, andparticularly a linear alkylene group is preferable. Moreover, R has, forexample, 1 to 30 carbon atoms, and preferably 10 to 25 carbon atoms.

Furthermore, R may be a group that is expressed by R¹-Q-R². Each of R¹and R² is a saturated or unsaturated hydrocarbon group. As in the caseof R, examples of hydrocarbon groups include chain hydrocarbon groups,alicyclic hydrocarbon groups, and aromatic hydrocarbon groups that areor are not substituted, and in particular, chain hydrocarbon groups arepreferable. Examples of chain hydrocarbon groups include an alkylenegroup, an alkenylene group, and an alkynylene group, and in particular,a linear alkylene group is preferable. R¹ and R² have, for example, 1 to30 carbon atoms in total, and preferably 10 to 25 carbon atoms in total.Moreover, Q is an oxy group (—O—), a carboxyl group (—CO—), an estergroup (—COO—), an oxycarbonyl group (—OCO—), or a carbonate group(—OCOO—).

Specific examples of the organic molecules include compounds expressedby the following formulae:HO—(CH₂)_(a)—SHHO—(CH₂)_(b)-Q-(CH₂)_(c)—SHHOOC—(CH₂)_(a)—SHHOOC—(CH₂)_(b)-Q-(CH₂)_(c)—SH

Herein, a is an integer of, for example, 1 to 30, preferably 10 to 25. band c are integers satisfying, for example, 1≦(b+c)≦30, preferably10≦(b+c)≦25. Q is the same as described above.

Furthermore, in the coating film, it is preferable to orient theconstituent molecules. As the orientation method, for example, a methodsimilar to the orientation treatment of the conductive organic thin filmas will be described in the seventh embodiment can be employed, but notlimited thereto.

Then, when the organic molecules are brought into contact with thesurfaces of the electrodes 4 a and 4 b, reactions occur between thereactive groups in the organic molecules and the surfaces of theelectrodes to form chemical bonds, preferably covalent bonds. Forexample, when the end reactive group is a mercapto group, this groupreacts with a metal constituting the electrodes to form a —S— bond. Thischemical bond allows the organic molecules to be fixed to the surface ofthe electrode, and thus the monomolecular film is formed.

Next, after the substrate is washed, if necessary, an organic thin film7 (i.e., precursor thin film) that serves as a precursor of theconductive organic thin film is formed on the surface of the insulatingfilm 5 on the substrate 2 as well as on the surfaces of themonomolecular films for coating 51 on the electrodes 4 a and 4 b, asshown in FIG. 11F. This precursor thin film 7 may be a monomolecularfilm or a monomolecular built-up film.

FIGS. 13A and 13B are schematic diagrams showing an example of theprecursor thin film 7 constituted by a monomolecular film. FIG. 13Ashows a portion formed on the insulating film 5, and FIG. 13B shows aportion formed on the surface of the monomolecular film for coating 51.In FIGS. 13A and 13B, numerals 11 through 14 are the same as in FIG. 3and numerals 51 through 53 are the same as in FIG. 12.

As shown in FIG. 13A, in a region between the electrodes, end-bondablegroups 13 in the organic molecules 14 are bonded to the surface of theinsulating film 5 on the substrate 2. Moreover, as shown in FIG. 13B, onthe electrodes 4 a and 4 b, the end-bondable groups 13 in the organicmolecules 14 are bonded to the surfaces of the monomolecular films forcoating 51. More specifically, the group 54 having active hydrogen andpresent at an end of the organic molecule 52 constituting themonomolecular film for coating 51 is bonded to the end-bondable group 13in the organic molecule 14 constituting the precursor thin film 7. Inthis manner, the organic molecules 14 are fixed to the surface of theinsulating film 5 and the surfaces of the monomolecular films forcoating 51 by chemical bonds, and thus the monomolecular film is formed.

The method for forming the precursor thin film 7 is the same as in thefirst embodiment. Furthermore, a conductive organic thin film 8 isformed by polymerizing the organic molecules constituting the precursorthin film 7 (FIG. 11G). This polymerization process is also the same asin the first embodiment.

FIGS. 14A and 14B are diagrams showing an example of the structure ofthe thin film after polymerization (i.e., conductive organic thin film8). FIGS. 14A and 14B show the conductive organic thin films 8 that canbe obtained by polymerizing the precursor thin films 7 shown in FIGS.13A and 13B, respectively. As shown in the drawings, in both regions onthe substrate and on the electrode, the conjugated-bondable groups 11 inthe organic molecules are bonded by polymerization to form conjugatedbond chains 15. Then, the formation of this conjugated bond chain 15forms a conductive network, and thus the thin film is provided withconductivity.

SIXTH EMBODIMENT

The method for forming the monomolecular film for coating having activehydrogen on its surface is not limited to the method as described above,and for example, a method of forming a precursor of the monomolecularfilm for coating on the surface of the electrode and then performing atreatment for providing active hydrogen on the surface of this precursormay be employed.

The precursor of the monomolecular film for coating is a monomolecularfilm that is chemically bonded to the surface of the electrode. As theorganic molecules that serve as material of this precursor, organicmolecules having a reactive group that can form a chemical bond with thesurface of the electrode at one end and a group that can be providedwith active hydrogen at the other end can be used. Examples of suchorganic molecules include a compound expressed by the chemical formulabelow.B—R—SH

In the chemical formula, B is a group that can be provided with activehydrogen. The group that can be provided with active hydrogen refers toa group that can be changed into a group having active hydrogen asdescribed above by performing an appropriate treatment after a film isformed by chemisorption.

Examples of such a group include a group containing an unsaturatedhydrocarbon group and a group containing an ester group. The groupcontaining an unsaturated hydrocarbon group can be changed into thegroup containing active hydrogen by performing an oxidation treatmentafter a film is formed. Examples of such a group containing anunsaturated hydrocarbon group include a group containing an alkenylgroup, an alkyl group, or the like, and specifically include H₂C═CH—,CH₃CH═CH—, and (CH₃)₃Si—C≡C—. Moreover, the group containing an estergroup can be changed into the group containing active hydrogen byperforming a hydrolysis treatment after a film is formed. Examples ofsuch a group containing an ester group include CH₃COO—, C₂H₅COO—, andC₃H₇COO—.

In the above chemical formula, R is the same as in the chemical formula(25).

Specific examples of such an organic molecule include compoundsexpressed by the following chemical formulae:H₂C═CH—(CH₂)_(a)—SHH₂C═CH—(CH₂)_(b)-Q-(CH₂)_(c)—SH(CH₃)Si—C≡C—(CH₂)_(a)—SH(CH₃)Si—C≡C—(CH₂)_(b)-Q-(CH₂)_(c)—SH

Herein, a is an integer of, for example, 1 to 30, and preferably 10 to25. b and c are integers satisfying, for example, 1≦(b+c)≦30, andpreferably 10≦(b+c)≦25. Moreover, Q is an oxy group (—O—), a carboxylgroup (—CO—), an ester group (—COO—), an oxycarbonyl group (—OCO—), or acarbonate group (—OCOO—).

After the precursor of the monomolecular film for coating is formed onthe surface of the electrode using the above-described organicmolecules, a treatment for providing active hydrogen to the surface ofthis precursor is performed. As the film formation method of theprecursor, for example, chemisorption can be employed. Specific filmformation method is the same as the film formation method of themonomolecular film for coating in the fourth embodiment except that thetype of the organic molecules to be used is different.

The treatment for providing active hydrogen on the surface of theprecursor refers to a treatment for changing the group that can beprovided with active hydrogen as described above into the group havingactive hydrogen. For example, when the group that can be provided withactive hydrogen is an unsaturated hydrocarbon group, this group can bechanged into the group having active hydrogen by performing a treatmentfor oxidizing the surface of the monomolecular film. As the oxidationmethod, for example, a method of irradiating the surface of themonomolecular film with energy rays can be employed. As the energy rays,for example, light rays such as infrared rays, ultraviolet rays, farultraviolet rays, and visible rays, radiations such as X-rays, andparticle beams such as electron beams can be applied. Moreover, thisirradiation with the energy rays is preferably carried out in anatmosphere containing moisture. With this method, the unsaturatedhydrocarbon group can be changed into, for example, a group containingan —OH group.

Furthermore, as another oxidation method, a method of bringing anoxidizing agent into contact with the surface of the monomolecular filmcan be employed. As an oxidizing agent, for example, potassiumpermanganate and hydrogen peroxide can be used. Moreover, as a methodfor contacting the oxidizing agent, a method of preparing an aqueoussolution of the oxidizing agent and immersing the substrate providedwith the monomolecular film in this aqueous solution can be applied. Inthis case, the unsaturated hydrocarbon group can be changed into, forexample, a group containing a —COOH group.

Also in this embodiment, it is preferable to orient the constituentmolecules of the coating film. As the orientation method, for example, amethod similar to the orientation treatment of the conductive organicthin film as will be described in the seventh embodiment can beemployed, but not limited thereto.

SEVENTH EMBODIMENT

In each of the above embodiments, before the polymerization process ofthe precursor thin film formed on the substrate via the insulating film,the organic molecules constituting the organic thin film may be orientedat a tilt. The reason for this is as follows. If the organic moleculesare oriented, the conjugated-bondable groups can be aligned in a certaindirection and also can be aligned in close proximity to each other.Consequently, polymerization of the organic molecules can proceed easilyand the conductivity of the conductive organic thin film that is formedafter the polymerization can be further improved.

FIG. 15A shows a schematic diagram of an example of an orientedmonomolecular film 61 that is obtained by orienting the monomolecularfilm 7 shown in FIG. 3, and FIG. 15B shows a schematic diagram of aconductive organic thin film 62 that is obtained by polymerizing theoriented monomolecular film 61 in FIG. 15A. In these drawings, the samemembers as in FIGS. 3 and 4 bear the same numerals.

Examples of the method for orienting at a tilt include the followingmethods.

(i) Rubbing

The surface of the organic thin film on the substrate is subjected torubbing using a rubbing apparatus, and thus the organic moleculesconstituting the organic thin film can be oriented in the rubbingdirection. Moreover, when the surface of the substrate is subjected torubbing using a rubbing apparatus as a pre-treatment process before theorganic thin film formation process, the organic thin film that isformed on the substrate via the insulating film also can be oriented. Inthis case, the orientation direction of the organic thin film is thesame as the rubbing direction. As a rubbing cloth that is used inrubbing process, for example, a cloth made of nylon or rayon ispreferable because the orientation accuracy can be improved.

(ii) Polarization

Irradiation with polarized light using a polarizing plate allows theorganic molecules constituting the organic thin film to be oriented inthe polarization direction. In this case, the orientation direction ofthe organic molecules is generally the same as the polarizationdirection. With such an orientation method using irradiation withpolarized light, damage of the organic thin film due to elimination ofthe organic molecule constituting the organic thin film from the surfaceof the insulating film, breakage of the organic molecule itself, and thelike can be prevented or suppressed. As the polarized light, linearlypolarized light with a wavelength in the visible region preferably isused.

(iii) Draining

When the organic thin film is formed by chemisorption, the substrate iswashed for the purpose of removing an unadsorbed organic molecule, sothat the organic thin film also can be oriented in this washing process.Specifically, for example, after the substrate is immersed in an organicsolvent for washing and the unadsorbed organic molecule is removed, thesubstrate is pulled up while maintaining a predetermined tilt angle withrespect to the liquid surface of the organic solvent for washing. Thus,the organic molecules constituting the organic thin film can be orientedin the direction in which the liquid flows, which is opposite to thedirection of pulling up (hereinafter, referred to as “drainingorientation”).

The draining method is not limited to the method of pulling up thesubstrate from the liquid, and a method of blowing a gas such as dry aironto the surface of the substrate from a constant direction andscattering a nonaqueous solvent in the same direction to remove thissolvent also can be employed. In this case, the direction in which thenonaqueous solvent is scattered corresponds to the draining directionand the organic molecules constituting the organic thin film can beoriented in this direction.

(iv) Orientation Using Fluctuation of Molecules during PolymerizationProcess in a Solution

In addition to the above-described orientation methods, for example,orientation can be achieved using fluctuation of molecules duringpolymerization. Among the organic molecules in the present invention,for example, in those containing a polar functional group, a fluctuationtends to occur even at about room temperature (25° C.) because of therotation of molecules when they are in a solution. Therefore, forexample, it is also possible to utilize the fluctuation of the moleculesin electrolytic polymerization process for orientation.

Each of the orientation methods as described above may be appliedindividually or a plurality of the orientation methods may be applied,and when different orientation methods are combined, it is preferable toadjust such that, for example, the rubbing direction, the polarizingdirection, and the draining direction are identical with each other forthe purpose of orienting molecules with a high accuracy.

The monomolecular film constituting the organic thin film may havepartially different orientation directions and orientation angles, andwhen the organic thin film is a built-up monomolecular film, theorientation direction and the orientation angle may be identical ordifferent between the monomolecular films, as long as the directions ofthe conductive networks (directions of connections between the firstelectrodes and the second electrodes) are identical between themonomolecular films.

The angle of tilt orientation φ of the monomolecular film is, forexample, but not limited to, in the range of 0°≦φ<90°, preferably in therange of 5°≦φ≦85°, and particularly preferably in the range of50°≦φ≦85°. As shown in FIG. 16, the angle of tilt orientation φ of theorganic molecule 14 in the monomolecular film refers to the tilt angleof the organic molecule with respect to the plane of the substrate,whereas the angle of the organic molecule with respect to the directionperpendicular to the plane of the substrate is represented by θ.

EIGHTH EMBODIMENT

The method for polymerizing the monomolecular film constituting theprecursor thin film to form the conductive network is not limited toelectrolytic polymerization as described above and may be, for example,catalytic polymerization or energy beam irradiation polymerization.Moreover, these polymerization methods can be combined, and it ispreferable to perform electrolytic polymerization in the final stage ofpolymerization process. Specific examples thereof include a combinationof performing at least catalytic polymerization or energy beamirradiation polymerization as prepolymerization and then, finallyperforming electrolytic polymerization. When prepolymerization isperformed in this manner to achieve partial polymerization to a certainextent and then partially polymerized polymers are bonded by the finalelectrolytic polymerization, for example, the polymerization time can bereduced. Each of these polymerization methods can be performed, forexample, in the following manner.

(i) Catalytic Polymerization

Catalytic polymerization is a conventionally known method and can beperformed in an organic solvent containing a catalyst. The catalyst canbe determined as appropriate in accordance with the type of the organicmolecules to be used and for example, a Ziegler-Natta catalyst and ametal halide catalyst can be used. It is preferable that the metalhalide catalyst contains, for example, Mo, W, Nb, or Ta as a metal, andspecific examples thereof include MoCl₅, WCl₆, NbCl₅, TaCl₅, Mo(Co)₅,W(CO)₆, Nb(CO)₅, and Ta(CO)₅. As the organic solvent, for example,toluene, dioxane, and anisole can be utilized.

The conditions for catalytic reaction can be determined as appropriatein accordance with the type of the organic molecules to be used and thelike, and for example, the temperature is set at room temperature andthe pressure is set at 1 Pa.

Examples of the conjugated-bondable groups in the organic molecules thatare polymerized by catalytic reaction include a pyrrolyl group, athienylene group, an acetylene group, and a diacetylene group.

(ii) Energy Beam Irradiation Polymerization

As the energy beams, for example, light rays such as infrared rays,ultraviolet rays, far ultraviolet rays, and visible rays, radiation suchas X-rays, and particle beams such as electron beams can be applied.Since the conjugated-bondable groups have different absorptionproperties depending on the type thereof, the type of the energy beams,and the irradiation conditions (amount of irradiation, irradiation time,etc.) may be determined as appropriate in accordance with, for example,the type of the conjugated-bondable groups in the organic molecules.Thus, the efficiency of polymerization reaction can be improved.Moreover, since a large number of types of conjugated-bondable groupshave absorptivity for energy beams, this method can be applied even tothe case where the monomolecular film is made of the organic moleculeshaving a variety of types of conjugated-bondable groups.

Examples of the conjugated-bondable groups that are polymerized byenergy irradiation include an acetylene group and a diacetylene group.Specifically, when the conjugated-bondable group is an acetylene group,irradiation with X-rays or an electron beam of 50-Mrad is preferable,whereas in the case of diacetylene, for example, irradiation with UVlight (100 mJ/cm²) is preferable.

When, for example, polarized ultraviolet rays, polarized far ultravioletrays, polarized X-rays, and the like are used as the energy beams, thetilt orientation treatment and the conductive network formation(polymerization) can be performed at the same time. When irradiated withpolarized energy beams in this manner, the organic moleculesconstituting the monomolecular film can be oriented at a tilt in apredetermined direction and also the organic molecules can beconjugated-bonded to each other, and therefore the manufacturing processcan be simplified.

Alternatively, it is also possible that the organic molecules arepolymerized by conjugated bonding and further conjugated-bonded by acrosslinking reaction after the polymerization to form the conductivenetwork. Specifically, for example, in the case where the organicmolecule has two or more conjugated-bondable groups, oneconjugated-bondable group is polymerized with another organic moleculeand subsequently further polymerization with still another organicmolecule is performed using the other conjugated-bondable group, andthus a conductive network having a different structure from that afterthe polymerization can be formed. In this manner, when polymerization isfollowed by further polymerization, the conductivity can be improvedeven more.

Specifically, for example, when the organic molecule has a diacetylenegroup as the conjugated-bondable group, one acetylene group can befirstly polymerized by energy beam irradiation polymerization orcatalytic polymerization and then, the other acetylene can bepolymerized by further catalytic polymerization or energy beampolymerization.

NINTH EMBODIMENT

Regarding the organic electronic device of the present invention, anexample of a three-terminal organic electronic device will be describedwith reference to FIG. 17. FIG. 17 is a schematic cross-sectional viewof the three-terminal organic electronic device, and the same members asin FIG. 1 bear the same numerals.

As shown in the drawing, the three-terminal organic electronic device 70is provided with a substrate 2 (e.g., Si substrate) that also serves asa third electrode (gate electrode), insulating films (e.g., SiO₂) 3 and5, first and second electrodes 4 a and 4 b, and a conductive organicthin film 8. The first electrode 4 a and the second electrode 4 b areformed on the substrate 2 via the insulating film 3. Furthermore, theconductive organic thin film 8 is formed on the substrate 2 so as tocoat a region between the two electrodes on the surface of thesubstrate. In the region between the two electrodes, this conductiveelectronic organic device 8 is formed on the substrate 2 via theinsulating film 5.

The first and the second electrodes 4 a and 4 b are coated with coatingfilms 71, and the respective electrodes and the conductive organic thinfilm are connected electrically via the coating films 71. The coatingfilms 71 are the same as those in the above embodiments.

Moreover, FIG. 17 illustrates a side contact structure in which the sidefaces of the electrodes are in contact with the conductive organic thinfilm, but the present invention is not limited to such a structure, and,for example, a top contact structure in which the top faces of theelectrodes are in contact with the conductive organic thin film is alsopossible.

Such an organic electronic device can be manufactured by applying amethod similar to that in the above embodiments, for example, using asilicon substrate as the substrate 2 and using SiO₂ as the insulatingfilms 3 and 5.

In this organic electronic device, when a voltage is applied between thefirst electrode 4 a and the second electrode 4 b and between the secondelectrode 4 b and the third electrode (Si substrate) 2, and the voltagebetween the second electrode 4 b and the third electrode 2 is changed,the electron injection rate in the conjugated bond chain within theconductive organic thin film 8 can be controlled, and consequently,current in the conductive organic thin film 8 between the firstelectrode 4 a and the second electrode 4 b can be controlled. Therefore,this organic electronic device can be used as a so-called FET-typeorganic electronic device. In this organic electronic device, theorganic molecules constituting the conductive organic thin filmpreferably have, for example, a polar functional group.

Regarding this three-terminal organic electronic device, the change inthe conductivity of the conductive organic thin film over time due tothe application of the voltage will be described with reference to FIG.18A, and the switching operation thereof will be described withreference to FIG. 18B. FIG. 18A is a graph qualitatively showing thecurrent and the voltage between the electrodes for the purpose ofshowing the change in the conductivity of the conductive organic thinfilm during application of the voltage to the third electrode (Sisubstrate). In FIG. 18A, the vertical axis indicates the current betweenthe first and the second electrodes. Moreover, since the voltage appliedto the third electrode is proportional to an electric field (appliedvoltage) acting on the conductive organic thin film, the voltage appliedbetween the first and the second electrodes and the voltage applied tothe third electrode become equivalent, and therefore the voltage appliedbetween the first and the second electrodes is indicated on thehorizontal axis. The change in the current is taken when the voltageapplied between the first and the second electrodes is constant.

As shown in the drawing, the current between the first and the secondelectrodes changes with the voltage applied to the third electrode andconverges on a certain value as the applied voltage increases, and thusit can be seen that the current is controlled within a range between acurrent value when the voltage is not applied to the third electrode(V=0) and the convergent current value. That is to say, the fact thatthat the conductivity of the conductive organic thin film is controlledby the voltage applied to the third electrode is indicated. In thismanner, the conductive organic thin film is made to shift between astable state in which a conductivity at the time of no voltageapplication is provided and a stable state in which a conductivity atthe time of application of a predetermined voltage is provided bychanging the applied voltage, and thus the conductivity of theconductive network can be switched.

FIG. 18B is a conceptual diagram of the switching operation of thethree-terminal organic electronic device and shows that the switchingoperation is performed between ON current (I_(V=ON)) in the state(V_(ON)) in which a predetermined voltage is applied to the thirdelectrode and OFF current (I_(V=OFF)) in the state (V_(OFF)) in which novoltage is applied, when a constant voltage is applied between the firstand the second electrodes. The horizontal axis indicates time, and aline L1 and a line L2 indicate voltage change and current change,respectively.

As shown in the drawing, it can be seen that the current between thefirst and the second electrodes, that is, the conductivity of theconductive organic thin film, can be switched depending on whether thevoltage applied to the third electrode is on or off. Although FIG. 18Bshows the switching by turning voltage on or off, it should beappreciated that the current also can be switched by applying twodifferent types of voltages to the third electrode.

EXAMPLES

Hereinafter, the contents of the present invention will be described byway of examples, but the present invention is not limited to thefollowing examples. In the following examples, “%” means percentage byweight.

Example 1

PEN, which is an organic molecule, was prepared and, using this, athree-terminal organic electronic device (FET) that is the same as inFIG. 17 of the ninth embodiment was produced, and the performancethereof was examined.

I. Synthesis of PEN

First, PEN expressed by chemical formula (9) below having a 1-pyrrolylgroup (C₄H₄N—) that can form a conductive network, an oxycarbonyl group(—OCO—) that is a polarizable functional group, and a trichlorosilylgroup (—SiCl₃) that causes a dehydrochlorination reaction with activehydrogen (e.g., hydrogen in a hydroxyl (—OH) group) on the surface ofthe insulating film was synthesized according to the following steps 1through 5.

Step 1: Synthesis of 6-bromo-1-(tetrahydropyranyloxy)hexane

First, 197.8 g (1.09 mol) of 6-bromo-1-hexanol were fed into a 500 mLreactor vessel and cooled to 5° C. or less, and further 102.1 g (1.21mol) of dihydropyran were dripped at a temperature of 10° C. or less.After completion of dripping, the mixture was warmed to room temperatureto carry out a reaction under stirring for one hour. Residues obtainedby this reaction were purified by silica gel column with hexane/IPE(diisopropylether)=5/1, and thus 263.4 g of6-bromo-1-(tetrahydropyranyloxy)hexane were obtained. The yield was90.9%. Formula (26) below shows the reaction formula of the step 1.

Step 2: Synthesis of N-[6-(tetrahydropyranyloxy)hexyl]pyrrole

First, 38.0 g (0.567 mol) of pyrrole and 200 mL of dehydratedtetrahydrofuran (THF) were fed into a 2 liter reactor vessel under astream of argon gas and cooled to 5° C. or less. Then, 354 mL (0.567mol) of 1.6M n-butyl lithium hexane solution were dripped into thismixture at 10° C. or less. After stirring for one hour at the sametemperature, 600 ml of dimethylsulfoxide were further added, and THF wasremoved by distillation by heating for solvent substitution. Then, 165.2g (0.623 mol) of 6-bromo-1-(tetrahydropyranyloxy)hexane were furtherdripped at room temperature. After dripping, the mixture was stirred for2 hours at the same temperature. Then, 600 mol of water were added tothe resultant reaction mixture to extract hexane and the organic layerwas washed with water. Furthermore, after drying with anhydrousmagnesium sulfate, the solvent was removed by distillation. Theresultant residues were purified by silica gel column with hexane/ethylacetate=4/1, and thus 107.0 g ofN-[6-(tetrahydropyranyloxy)hexyl]pyrrole were obtained. The yield was75.2%. Formula (27) below shows the reaction formula of the step 2.

Step 3: Synthesis of N-(6-hydroxyhexyl)-pyrrole

First, 105.0 g (0.418 mol) of N-[6-(tetrahydropyranyloxy)hexyl]pyrroleobtained in the step 2, 450 mL of methanol, 225 mL of water, and 37.5 mLof concentrated hydrochloric acid were fed into a one-liter reactorvessel and stirred for six hours at room temperature. The resultantreaction mixture was poured into 750 mL of saturated brine and IPE wasextracted. The organic layer was washed with saturated brine and furtherdried with anhydrous magnesium sulfate, and the solvent was removed bydistillation. Then, the resultant residues were purified by silica gelcolumn with n-hexane/ethyl acetate=3/1, and thus 63.1 g ofN-(6-hydroxyhexyl)-pyrrole were obtained. The yield was 90.3%. Formula(28) below shows the reaction formula of the step 3.

Step 4: Synthesis of N-[6-(10-undecenoiloxy)hexyl]-pyrrole

First, 62.0 g (0.371 mol) of N-(6-hydroxyhexyl)-pyrrole, 33.2 g (0.420mol) of dry pyridine, and 1850 ml of dry toluene were fed into a 2 literreactive vessel, and a solution of 75.7 g (0.373 mol) of10-undecenoilchloride in 300 mL of dry toluene were further dripped at20° C. or less. Dripping time was 30 minutes. Then, the mixture wasstirred for one hour at the same temperature. The resultant reactionmixture was poured into 1.5 liters of ice water and acidified with 1Nhydrochloric acid. Furthermore, ethyl acetate was extracted, and theorganic layer was washed with water and with saturated brine and driedwith anhydrous magnesium sulfate, and then the solvent was removed toobtain 128.2 g of a crude substance. This substance was purified bysilica gel column with n-hexane/acetone=20/1, and thus 99.6 g ofN-[6-(10-undecenoiloxy)hexyl]-pyrrole were obtained. The yield was80.1%. Formula (29) below shows the reaction formula of the step 4.

Step 5: Synthesis of PEN

First, 2.0 g (6.0×10⁻³ mol) of N-[6-(10-undecenoiloxy)hexyl]-pyrrole,0.98 g (7.23×10⁻³ mol) of trichlorosilane, and 0.01 g of 5% isopropylalcohol solution of H₂PtCl₆.6H₂O were fed into a 100 ml pressureresistant test tube provided with a cap and reacted for 12 hours at 100°C. After treating this reaction liquid with active carbon, low boilingpoint components were removed by distillation under a reduced pressureof 2.66×10³ Pa (20 Torr), and thus 2.3 g of PEN were obtained. The yieldwas 81.7%. Formula (30) below shows the reaction formula of the step 5.

A trimethoxysilyl group can be substituted for a trichlorosilyl group atan end of PEN by causing a dehydrochlorination reaction by stirring PENwith methyl alcohol in a molar amount three times as much as PEN in themoles at room temperature (25° C.). The hydrogen chloride generated bythis reaction can be separated in the form of sodium chloride by addingsodium hydroxide, if necessary.

Regarding the obtained PEN, FIG. 19 shows a chart of NMR, and FIG. 20shows a chart of infrared absorption spectrum (IR). Measurementconditions for NMR and IR are shown below.

(NMR)

-   (1) Measuring apparatus: apparatus name AL300 (manufactured by JEOL.    Ltd)-   (2) Measurement conditions: ¹H-NMR (300 MHz), measurement by    dissolving 30 mg of a sample in CDCl₃    (Infrared Absorption Spectrum: IR)-   (1) Measuring apparatus: apparatus name 270-30 model (manufactured    by Hitachi, Ltd.)-   (2) Measurement conditions: neat (measurement by a sample being    sandwitched between two NaCl plates)    II. Formation of Electrodes and Coating Films

First, a substrate made of Si was prepared, and a SiO₂ film that servesas an insulating film was formed on the surface of the substrate. TheSiO₂ film was formed by oxidization of the surface of the Si substrateby immersing this substrate in 10% nitric acid for one hour.

Next, a Ni thin film (film thickness 0.6 μm (6000 angstrom)) wasevaporated onto the surface of the SiO₂ film on the substrate. Then, theNi thin film was etched by the photolithographic method to form two Nielectrodes both having a gap distance of 10 μm, a length of 30 μm, and awidth of 100 μm.

Furthermore, after forming a SiO₂ film again as an insulating film onthe surface of the substrate where the electrodes were not formed, thesubstrate was immersed in a substitution-type gold plating bath (productname Aurolectroless SMT-301: manufactured by Meltex Inc.) containinggold potassium cyanide. Then, a reaction was carried out for 10 minutesat 85° C. while stirring the solution in the gold plating bath, and thusthe entire surface of each of the Ni electrodes on the substrate wascoated with an Au layer as a metal thin film for coating. The thicknessof the Au layer with which the top face of the Ni electrode was coatedwas about 0.8 μm, and the thickness of the Au layer with which the sidefaces of the Ni electrode were coated was about 0.8 μm.

III. Method for Forming Precursor Thin Film

First, the obtained PEN was diluted with dehydrated dimethyl siliconesolvent to a concentration of 1 wt % to prepare a chemisorptionsolution.

Then, the substrate on which the electrodes were formed was immersed inthe previously prepared chemisorption solution for one hour at roomtemperature (25° C.), and thus a precursor thin film was formed on thesurface of the insulating film on the substrate. Unreacted PEN remainingon the substrate 2 was removed by washing with anhydrous chloroform.

A large number of hydroxyl groups containing active hydrogen are presenton the surface of the insulating film 3, so that when the substrate isimmersed in the chemisorption solution as described above, adehydrochlorination reaction occurs between these hydroxyl groups andtrichlorosilyl groups (—SiCl₃) at the ends of PEN, and thus PEN isadsorbed. Therefore, a monomolecular film made of molecules expressed bychemical formula (31) below that are covalently bonded to the surface ofthe insulating film 3 was formed as the precursor thin film.

IV. Orientation of Organic Thin Film

As described above, orientation of the monomolecular film was performedat the same time of removing the unreacted PEN by washing the substrateon which the monomolecular film was formed with a chloroform solution.The substrate was immersed in a chloroform solution and washed, and whenpulled up from the solution, the substrate was pulled up vertically sothat the liquid flows in the direction parallel to the direction fromthe first electrode formed on the surface of the insulating film on thesubstrate to the second electrode. Thus, the monomolecular filmprimarily oriented in the direction from the first electrode toward thesecond electrode was formed.

V. Electrolytic Polymerization Method

The substrate was immersed in a pure water solution, and themonomolecular film was subjected to electrolytic polymerization byapplying a voltage between the first electrode and the second electrode,and thus a conductive organic thin film was formed. The conditions forthe electrolytic polymerization were that the electric field was 5 V/cm,the reaction temperature was at 25° C., and the reaction time was 5hours. A conductive network was formed by this electrolyticpolymerization. In this conductive network, conjugated bonds of theorganic molecules are formed in a self-assembling manner along thedirection of the electric field, and therefore when the polymerizationis completely finished, the first electrode and the second electrode areelectrically connected by this conductive network. Chemical formula (32)below shows a unit of the obtained conductive organic thin film.

The conductive organic thin film obtained in this manner had a filmthickness of about 2.0 nm, a thickness of about 0.2 nm in a polypyrroleportion, a length of 10 mm, and a width of 100 μm. Moreover, the angleof tilt orientation of the organic molecules (PEN) constituting thisconductive organic thin film was about 85°.

Finally, the substrate was made accessible as the third electrode, andthus the three-terminal organic electronic device can be manufactured.In this three-terminal organic electronic device, the first electrodeand the second electrode were connected by the conductive network madeof a polypyrrole-based conjugated bond chain.

VI. Measurement

(1) Properties of Conductive Organic Thin Film

The performance of the obtained conductive organic thin film wasexamined using a commercially available atomic force microscope (AFM)(manufactured by Seiko Instruments Inc., SAP 3800N). The electricalconductivity ρ under the conditions that the voltage was 1 mV and thecurrent was 160 nA in AFM-CITS mode was ρ>1×10⁷ S/cm at room temperature(25° C.) without doping. This value results from the fact that theampere meter used was capable of determining only up to 1×10⁷ S/cm andthus the indicator swung past the maximum. Considering the fact that theelectrical conductivity of gold, which is a metal having a goodconductivity, is 5.2×10⁵ S/cm at room temperature (25° C.) and that ofsilver is 5.4×10⁵ S/cm, it can be said that the electrical conductivityρ of the conductive organic thin film in this example indicatesremarkably high conductivity. Based on the above value, the conductiveorganic thin film in the present invention can be referred to as “supermetal conductive film”.

(2) Properties of Three-Terminal Organic Electronic Device

Then, regarding the obtained three-terminal organic electronic device,when a voltage of 0 V was applied between the first electrode and thethird electrode (substrate) while applying a voltage of 1 V between thefirst electrode and the second electrode, a current of about 1 mA flowedbetween the first electrode and the second electrode. Subsequently, whena voltage of 5 V was applied between the first electrode and the thirdelectrode (substrate) while applying a voltage of 1 V between the firstelectrode and the second electrode, the current value between the firstelectrode and the second electrode became substantially 0 A. Then, whenthe voltage between the first electrode and the third electrode wasturned to 0 V from 5 V, the current flow was restored between the firstelectrode and the second electrode and the original conductivity wasreproduced.

It seems that when applying a voltage of 5 V between the third electrode(substrate) and the first electrode, polarization of an oxycarbonylgroup (—OCO—) that is a polar functional group was increased and thus adistortion occurred in the conjugated bond chain formed of polypyrroleto cause a reduction in the degree of conjugation of the conjugatedbond, which led to deterioration in the conductivity of the conductivenetwork. Then, it seems that by turning the voltage to its originalvalue, the polarization was returned to its normal state, the distortionwas restored, and the degree of conjugation was recovered. That is tosay, it can be said that with the voltage applied between the firstelectrode and the third electrode (substrate), the conductivity of theconductive network could be controlled and the current flowing betweenthe first electrode and the second electrode could be switched.

(3) Properties of Electrodes

The electrodes could be prevented from being corroded by coating theentire surfaces of the Ni electrodes with the Au layers and had goodcontact with the conductive organic thin film.

Example 2

TEN, which is an organic molecule, was prepared and, using this, anorganic electronic device (FET) that is the same as in Example 1 wasproduced, and the performance thereof was examined.

I. Synthesis of TEN

TEN expressed by chemical formula (11) below was synthesized accordingto the following steps 1 through 5.

Step 1: Synthesis of 6-bromo-1-(tetrahydropyranyloxy)hexane

6-bromo-1-(tetrahydropyranyloxy)hexane was synthesized in the samemanner as in Example 1 (the formula (26): step 1). First, 197.8 g (1.09mol) of 6-bromo-1-hexanol were fed into a 500 mL reactor vessel andcooled to 5° C. or less, and then 102.1 g (1.21 mol) of dihydropyranwere dripped at 10° C. or less. After completion of dripping, themixture was warmed to room temperature and stirred for one hour. Theobtained residues were subjected to silica gel column and purified usinga mixed solvent of hexane/diisopropylether (IPE) (volume ratio 5:1) asan eluting solvent, and thus 263.4 g of6-bromo-1-(tetrahydropyranyloxy)hexane were obtained. The yield in thiscase was 90.9%.

Step 2: Synthesis of 3-[6-(tetrahydropyranyloxy)hexyl]thiophene

3-[6-(tetrahydropyranyloxy)hexyl]thiophene was synthesized by performinga reaction expressed by chemical formula (33) below.

First, 25.6 g (1.06 mol) of shaved magnesium were fed into a 2 L reactorvessel under a stream of argon gas, and further 4 L of drytetrahydrofuran (dry THF) solution containing 140.2 g (0.529 mol) of6-bromo-1-(tetrahydropyranyloxy)hexane were dripped at room temperature.At this time, the dripping time was one hour and 50 minutes and anexothermic reaction was caused. Then, the mixture was stirred for 1.5hours at room temperature, and thus a Grignard reagent was prepared.

Next, 88.2 g (541 mol) of 3-bromothiophene and 3.27 g ofdichlorobis(triphenylphosphine)nickel (II) were fed into another 2 Lreactor vessel under a stream of argon gas, and the whole Grignardreagent prepared was dripped at room temperature. At this time, thetemperature in the reactor vessel was kept at room temperature (50° C.or less) and dripping time was 30 minutes. After dripping, the mixturewas stirred for 23 hours at room temperature. This reaction mixture wasadded to 1.3 L of 0.5N HCl maintained at 0° C. and IPE was extracted.The obtained organic layer was washed with water and further washed withsaturated brine, and then dried by adding anhydrous magnesium sulfate.Then, the solvent was removed by distillation, and thus 199.5 g of acrude substance containing 3-[6-(tetrahydropyranyloxy)hexyl]-thiophenewere obtained. This crude substance was subjected to the next step 3without being purified.

Step 3: Synthesis of 3-(6-hydroxyhexyl)-thiophene

3-(6-hydroxyhexyl)-thiophene was synthesized by performing a reactionexpressed by chemical formula (34) below.

First, 199.5 g of the unpurified3-[6-(tetrahydropyranyloxy)hexyl]-thiophene obtained in the step 2, 450mL of methanol, 225 mL of water, and 37.5 mL of concentratedhydrochloric acid were fed into a 1 L reactor vessel and reacted understirring for 6 hours at room temperature. This reaction mixture wasadded to 750 mL of saturated brine and IPE extraction was performed.Then, the obtained organic layer was washed with saturated brine andfurther dried with anhydrous magnesium sulfate, and subsequently thesolvent was removed by distillation to obtain 148.8 g of a crudesubstance containing 3-(6-hydroxyhexyl)-thiophene. This crude substancewas subjected to silica gel column and purified using a mixed solvent ofn-hexane/ethyl acetate (volume ratio 3:1) as an eluting solvent, andthus 84.8 g of 3-(6-hydroxyhexyl)-thiophene were obtained. The yield inthis case was 87.0% with respect to the crude substance containing3-[6-(tetrahydropyranyloxy)hexyl]-thiophene obtained in the step 2.

Step 4: Synthesis of 3-[6-(10-undecenoiloxy)hexyl]-thiophene

3-[6-(10-undecenoiloxy)hexyl]-thiophene was synthesized by performing areaction expressed by chemical formula (35) below

First, 84.4 g (0.458 mol) of the crude substance containing3-(6-hydroxyhexyl)-thiophene obtained in the step 3, 34.9 g (0.442 mol)of dry pyridine, and 1450 mL of dry toluene were fed into a 2 L reactivevessel, and further 250 mL of dry toluene solution containing 79.1 g(0.390 mol) of 10-undecenoilchloride were dripped in a condition at 20°C. or less. Dripping time was 30 minutes, and subsequently a reactionwas carried out under stirring for 23 hours at the same temperature. Theresultant reaction mixture was added to 2 L of ice water, and further 75mL of 1N hydrochloric acid were added. This mixture was subjected toethyl acetate extraction, and the obtained organic layer was washed withwater and further washed with saturated brine, and then dried by addinganhydrous magnesium sulfate. Then, the solvent was removed, and thus161.3 g of a crude substance containing3-[6-(10-undecenoiloxy)hexyl]-thiophene were obtained. This crudesubstance was subjected to silica gel column and purified using a mixedsolvent of n-hexane/acetone (volume ratio 20:1) as an eluting solvent,and thus 157.6 g of 3-[6-(10-undecenoiloxy)hexyl]-thiophene wereobtained. The yield in this case was 98.2% with respect to the crudesubstance containing 3-(6-hydroxyhexyl)-thiophene obtained in the step3.

Step 5: Synthesis of TEN

TEN was synthesized by performing a reaction expressed by chemicalformula (36) below.

(a) First, 10.0 g (2.86×10⁻² mol) of3-[6-(10-undecenoiloxy)hexyl]-thiophene, 4.65 g (3.43×10⁻⁴ mol) oftrichlorosilane, and 0.05 g of an isopropyl alcohol solution containingH₂PtCl₆.6H₂O in the proportion of 5 wt % were fed into a 100 ml pressureresistant test tube provided with a cap and reacted for 14 hours at 100°C. After treating this reaction liquid with active carbon, low boilingpoint components were removed by distillation under a reduced pressure.The condition for the reduced pressure was 2.66×10³ Pa (20 Torr).

(b) In the same manner, 39.0 g (1.11×10⁻¹ mol) of3-[6-(10-undecenoiloxy)hexyl]-thiophene, 18.2 g (1.34×10⁻¹ mol) oftrichlorosilane, and 0.20 g of the isopropyl alcohol solution containingH₂PtCl₆.6H₂O in the proportion of 5 wt % were fed into a 100 ml pressureresistant test tube provided with a cap and reacted for 12 hours at 100°C. After treating this reaction liquid with active carbon, low boilingpoint components were removed by distillation under a reduced pressure.The condition for the reduced pressure was as described above.

Then, residues obtained in (a) and (b) were mixed and argon gas waspassed through this mixture for one hour to remove hydrochloric acidgas, and thus 65.9 g of the targeted TEN were obtained. The yield inthis case was 97.2% with respect to the crude substance containing3-[6-(10-undecenoiloxy)hexyl]-thiophene obtained in the step 4.

The obtained TEN was subjected to IR analysis and NMR analysis. Theconditions and the results thereof will be described below. FIG. 21shows a chart of NMR and FIG. 22 shows a chart of IR.

(NMR)

-   (1) Measuring apparatus: apparatus name AL300 (manufactured by JEOL.    Ltd)    (2) Measurement conditions: ¹H-NMR (300 MHz), measurement by    dissolving 30 mg of a sample in CDCl₃    (Infrared Absorption Spectrum: IR)-   (1) Measuring apparatus: apparatus name 270-30 model (manufactured    by Hitachi, Ltd.)-   (2) Measurement conditions: neat (measurement by a sample being    sandwitched between two NaCl plates)    II. Manufacturing of Three-Terminal Organic Electronic Device

A three-terminal organic electronic device was manufactured in the samemanner as in Example 1 except that the obtained TEN was used.

A conductive organic thin film in the obtained organic electronic devicehad a film thickness of about 2.0 nm, a thickness of about 0.2 nm in apolythiophene portion, a length of 10 mm, and a width of 100 μm, and wastransparent in visible light. Chemical formula (37) below shows thestructure of one unit in this conductive organic thin film.

III. Measurement(1) Properties of Conductive Organic Thin Film

The performance of the obtained conductive organic thin film wasexamined under the same conditions, and the electrical conductivity ρthereof was ρ>1×10⁷ S/cm at room temperature (25° C.) without doping.Thus, this conductive organic thin film exhibited a remarkably highconductivity as in the case of the conductive organic thin film inExample 1. Moreover, the angle of tilt orientation of the organicmolecules (TEN) constituting this conductive organic thin film was about75°.

(2) Properties of Three-Terminal Organic Electronic Device

The properties of the obtained three-terminal organic electronic devicewere examined in the same manner as in Example 1, and the same result asin Example 1 was obtained.

(3) Properties of Electrodes

Even the side faces of the electrodes could be sufficiently coated withthe Au layers As by performing electroless gold plating on the entiresurfaces of the Ni electrodes, so that the electrodes could be preventedfrom being corroded and had good contact with the conductive organicthin film.

Example 3

A three-terminal organic electronic device was produced in the samemanner as in Example 1 except that after evaporating a Ti thin film(film thickness 0.1 μm) onto the surface of the insulating film on thesubstrate, a Ni thin film (film thickness 0.5 μm) was formed on the Tithin film by continuous evaporation, and these thin films were etched bythe photolithographic method to form electrodes, each constituted by alayered product formed of a Ti layer and a Ni layer, and then theelectrodes were coated with Au layers as the coating films. Theelectrodes were subjected to substitution-type gold plating for 10minutes at 85° C., so that even the side faces of the Ti layers wereplated with Au, and thus the entire surfaces of the electrodes werecoated with the Au layers. The thickness of the Au layer on the top faceof the electrode was about 0.8 μm and the thickness of the Au layers onthe side faces of the electrode was about 0.8 μm.

Even when the electrodes were layered products each consisting of the Tilayer and the Ni layer as above, the Ti layers and the Ni layers couldbe prevented from being corroded by coating the entire surfaces of theelectrodes with the Au layers, and also the electrodes had good contactwith the conductive organic thin film.

Example 4

The compound expressed by the formula (10) was prepared by performingsyntheses in the same manner as in Example 1 except that 8-bromo-octanolwas used in place of 6-bromo-1-hexanol in the manufacturing step 1 ofPEN and 6-hexenylchloride was used in place of 10-undecenoilchloride inthe manufacturing step 4. A three-terminal organic electronic device wasproduced using this compound in the same manner as in Example 1, and theobtained conductive organic thin film and three-terminal organicelectronic device showed the same results as in Example 1.

Example 5

The compound expressed by the formula (12) was prepared by performingsyntheses in the same manner as in Example 2 except that 8-bromo-octanolwas used in place of 6-bromo-1-hexanol in the manufacturing step 1 ofTEN and 6-hexenylchloride was used in place of 10-undecenoilchloride inthe manufacturing step 4. A three-terminal organic electronic device wasproduced using this compound in the same manner as in Example 1, and theobtained conductive organic thin film and three-terminal organicelectronic device showed the same results as in Example 1.

Example 6

A two-terminal organic electronic device that is the same as in FIG. 1described in the first embodiment was produced using organic moleculeshaving a photoresponsive functional group, and the performance thereofwas examined. In this example, an insulative glass substrate was used asthe substrate, and thus the insulating films 3 and 8 shown in FIG. 1were not formed.

I. Formation of Electrodes and Formation of Organic Thin Film

Electrodes and coating films were formed in the same manner as inExample 1. On the other hand, a chemisorption solution was prepared byusing organic molecules of chemical formula (38) below containing anethynylene group (—C≡C—) to be conjugated-bonded by polymerization, anazo group (—N═N—) that is a photoresponsive functional group to bephotoisomerized, and a trichlorosilyl group (—SiCl₃) that causes areaction with active hydrogen (e.g., hydroxyl group (—OH)) on thesurface of the substrate as the organic molecules and diluting theseorganic molecules with dehydrated dimethyl silicone solvent to aconcentration of 1%.(CH₃)₃Si—C≡C—(CH₂)₆—N═N—(CH₂)₈—SiCl₃  (38)

Then, an organic thin film was formed in the same manner as in Example 1except that the chemisorption solution containing the organic moleculeswas used. Since a large number of hydroxyl groups containing activehydrogen are present on the surface of the glass substrate, thetrichlorosilyl groups (—SiCl₃) in the organic molecules caused adehydrochlorination reaction with the hydroxyl groups and thus arecovalently bonded to the surface of the substrate. Chemical formula (39)below shows a unit constituting the obtained organic thin film(monomolecular film).

II. Orientation

Next, the precursor thin film formed on the surface of the substrate wassubjected to rubbing. This process was carried out by bringing a roll 82wrapped around with a rubbing cloth 81 into contact with the surface ofthe substrate provided with the precursor thin film while rotating theroll at a predetermined rate, and at the same time, moving the substrateat a predetermined speed, as shown in FIG. 23. The rubbing process wasperformed using a rubbing roll having a diameter of 7 cm and wrappedaround with a rubbing cloth made of rayon (manufactured by YOSHIKAWACHEMICAL CO., LTD.: YA-20-R) under the conditions that the nip width was11.7 mm, the rotation rate of the roll was 1200 revolutions/sec and thesubstrate transporting speed was 40 mm/sec.

III. Catalytic Polymerization Method

The glass substrate was immersed in a toluene solvent containing aZiegler-Natta catalyst (5×10⁻² mol/L triethylalminum solution and2.5×10⁻² mol/L tetrabutyltitanate solution) to perform catalyticpolymerization of ethynylene groups in the organic moleculesconstituting the organic thin film. Thus, a conductive organic thin filmhaving a conductive network formed of a polyacetylene-based conjugatedbond chain was obtained. The first electrode and the second electrodeare connected electrically by this polyacetylene-based conductivenetwork. The film thickness of the obtained organic thin film was about2.0 nm, the length was about 10 mm, and the width was about 100 μm.Formula (40) below shows a unit constituting the obtained conductiveorganic thin film.

IV. Measurement(1) Properties of Two-Terminal Organic Electronic Device

When the conductive organic thin film of the obtained two-terminalorganic electronic device was irradiated with visible light and then avoltage was applied between the first electrode and the secondelectrode, current flowed between the electrodes because the electrodesare connected by the polyacetylene-based conductive network of theorganic conductive thin film. Specifically, a current of about 100 nAflowed at a voltage of 1 V. Subsequently, when the conductive organicthin film was irradiated with ultraviolet light, the current valuebecame substantially 0 A because the azo groups in the organic moleculesconstituting the conductive organic thin film changed from the cis-forminto the trans-form. Then, when irradiated with visible light again, theazo groups changed from the trans-form into the cis-form and currentthat is the same as the original current flowed, and thus it was foundthat the conductivity of the conductive organic thin film was restored.

It is seems that such a reduction in the conductivity due to irradiationwith ultraviolet light results from a reduction in the conductivity ofthe conductive organic thin film because the polyacetylene-basedconjugated bonds in the conductive organic thin film are distorted byphotoisomerization (change from the trans-form into the cis-form) of theazo groups. That is to say, it can be said that the current flowingbetween the first electrode and the second electrode could be switchedby controlling the conductivity of the conductive organic thin film(conductivity of the conductive network) by irradiation with light.

When the polyacetylene-based conjugated bonds are used as the conductivenetwork, the lower the degree of polymerization is, the higher theresistance becomes. That is to say, the ON current decreases. However,in such a case, the ON current could be increased by diffusing, that is,doping, a dopant substance (e.g., halogen gas or Lewis acid as anacceptor molecule and an alkali metal or ammonium salt as a donormolecule) having a charge-transfer type functional group into theconductive network. For example, in the case where the conductivemonomolecular film in this example was doped with iodine, when a voltageof 1 V was applied between the first electrode and the second electrode,a current of 0.2 mA flowed.

When a greater ON current is required, the distance between the firstelectrode and the second electrode can be decreased or the widths of theelectrodes can be increased, and when a still greater ON current isrequired, it is preferable that the conductive organic thin film is amonomolecular built-up film.

(2) Properties of Electrodes

The Ni layers could be prevented from being corroded by coating theentire surfaces of the electrodes with the Au layers, and also theelectrodes had good contact with the conductive organic thin film.

Example 7

A two-terminal organic electronic device was produced in the same manneras in Example 6 using organic molecules having a photoresponsivefunctional group expressed by formula (17) below, and the performancethereof was examined. In this example, an insulative glass substrate wasused as the substrate, so that the insulating films were not formed.

First, an organic thin film 9 was formed on a glass substrate 2 on whichelectrodes were formed in the same manner as in Example 6 except that achemisorption solution was prepared by diluting organic molecules of thechemical formula (17) with a dehydrated dimethyl silicone solution to aconcentration of 1 wt %. Then, the organic thin film 9 was immersed in achloroform solution and washed, and draining orientation was performedin the same manner as in Example 1. Formula (41) below shows a unitstructure constituting the obtained organic thin film.

Next, the glass substrate 2 was immersed in a pure water solution and avoltage was applied between the first electrode and the second electrode(electric field 5 V/cm) to perform electrolytic polymerization of theorganic thin film (reaction temperature was 25° C. and reaction time was8 hours). A polypyrrole-based conductive network was formed by thiselectrolytic polymerization, and the two electrodes were electricallyconnected. At this time, conjugated bonds of the organic molecules areformed in a self-assembling manner along the direction of the electricfield, and therefore when polymerization is completely finished, the twoelectrodes are electrically connected by the conductive network. Formula(42) below shows a structure of a unit constituting the obtainedconductive organic thin film.

The obtained organic conductive film had a film thickness of about 2.0nm, a thickness of about 0.2 nm in a polypyrrole chain portion, a lengthof 10 mm, and a width of 100 μm, and was transparent in visible light.

IV. Measurement

(1) Properties of Conductive Organic Thin Film

The electrical conductivity ρ of the conductive organic thin film wasdetermined using a commercially available atomic force microscope (AFM)(manufactured by Seiko Instruments Inc., SAP 3800N) in AFM-CITS mode(voltage: 1 mV, current: 160 nA), and the result was ρ: 1×10³ S/cm atroom temperature (25° C.) without doping. Furthermore, the electricalconductivity ρ became 1×10⁴ S/cm by doping the conductive organic thinfilm with iodine ions.

(2) Properties of Two-Terminal Organic Electronic Device

Regarding this two-terminal organic electronic device, the change in thecurrent was determined in the same manner as in Example 6, and as in thecase of Example 6, the current flowing between the first electrode andthe second electrode could be switched by controlling the conductivityof the conductive organic thin film (conductivity of the conductivenetwork) by irradiation with light.

(3) Properties of Electrodes

The Ni layers could be prevented from being corroded by coating theentire surfaces of the electrodes with the Au layers as described above,and also the electrodes had good contact with the conductive organicthin film.

Example 8

PEN was synthesized in the same manner as in Example 1. Then, an organicelectronic device (FET) was produced in the substantially same manner asin Example 1 except that a polypyrrole film was formed as the coatingfilm, and the performance thereof was examined.

In this example, each of the electrodes had a structure in which thesurface of an inner layer constituted by a Ni layer was coated with anouter layer constituted by an Au layer. Such an electrode was formed bythe same method as that for forming the electrodes and the metal filmsfor coating in Example 1.

First, a pyrrole solution was prepared by dissolving pyrrole in anethanol solvent to a concentration of 0.1 mol/L, and a substrate onwhich the electrodes were formed was immersed in the pyrrole solution.Furthermore, a platinum electrode was immersed as a cathode and theelectrodes on the substrate were immersed as anodes, and a voltage wasapplied between each of the anodes and the cathode to cause electrolyticpolymerization of pyrrole, and thus polypyrrole films were formed as thecoating films on the surfaces of the anodes (the first electrode and thesecond electrode). The conditions for this electrolytic polymerizationwere that the electric field was 2 v/cm, the time was 60 minutes, andthe temperature was 25° C. The film thicknesses of the polypyrrole filmsformed on the surfaces of the first electrode and the second electrodewere about 1 nm.

A device in which the conductive organic film was in good contact withthe electrodes was provided by coating the electrodes with theconductive polymeric films (polypyrrole films) as above. In particular,the polypyrrole film having such conductivity and the polypyrrole bondchain in the conductive organic thin film can be directly bonded byelectrolytic polymerization, so that a connection with almost no energybarrier can be achieved.

Example 9

An organic electronic device (FET) was produced in the same manner as inExample 8 except that a monomolecular film having1-(mercaptononadecyl)pyrrole as a constituent molecule was formed as thecoating film by the following method.

First, 1-(mercaptononadecyl)pyrrole that is the constituent molecule wasdissolved in an acetonitrile solvent to a concentration of 0.01 mol/L.Then, the substrate was immersed in this solution, and monomolecularfilms that are the coating films were formed on the surfaces of the Aulayers of the electrodes.

The film thicknesses of the monomolecular films formed on the surfacesof the first electrode and the second electrode were about 1 nm. Theobtained result was that, as in the case of Example 8, the electrodeshad good contact with the conductive organic thin film in this device.

Example 10

First, TEN was synthesized in the same manner as in Example 3. Then, anorganic electronic device (FET) was produced in the substantially samemanner as in Example 3 except that a polythiophene film was formed asthe coating film by the following method, and the performance thereofwas examined.

In this example, each of the electrodes had a structure in which thesurface of an inner layer formed of a Ni layer was coated with an outerlayer formed of an Au layer. Such an electrode was formed by the samemethod as that for forming the electrodes and the metal films forcoating in Example 1.

First, thiophene was dissolved in an ethanol solvent to a concentrationof 0.1 mol/L to prepare a thiophene solution, and a substrate on whichelectrodes were formed was immersed in the thiophene solution.Furthermore, a platinum electrode was immersed as a cathode and theelectrodes on the substrate were immersed as anodes, and a voltage wasapplied between the cathode and each of the anodes to cause electrolyticpolymerization of pyrrole, and thus polythiophene films were formed onthe surfaces of the anodes. The conditions for this electrolyticpolymerization were that the electric field was 3 v/cm, the time was 10minutes and the temperature was 25° C. The film thicknesses of thepolythiophene films formed on the surfaces of the first electrode andthe second electrode were about 1 nm.

Consequently, a device in which the conductive electronic thin film hadgood contact with the electrodes was obtained by coating the electrodeswith the coating films (polythiophene films). In particular, thepolythiophene film having such conductivity and a polythiophene bondchain in the conductive organic thin film can be directly bonded byelectrolytic polymerization, so that a connection with almost no energybarrier can be achieved.

Example 11

An organic electronic device (FET) was produced in the same manner as inExample 10 except that a monomolecular film having1-(mercaptohexadecyl)thiophene as a constituent molecule was formed asthe coating film.

First, 1-(mercaptohexadecyl)thiophene that is the constituent moleculewas dissolved in an ethanol solvent to a concentration of 0.01 mol/L,and the substrate was immersed in this solution to form monomolecularfilms for coating on the surfaces of the outer layers (Au layers) of theelectrodes.

The film thicknesses of the monomolecular films for coating formed onthe surfaces of the first electrode and the second electrode were about1 nm. The obtained three-terminal organic electronic device was a devicein which the contact with the conductive organic thin film was good, asin the case of Example 3.

Example 12

A three-terminal organic electronic device was produced in the samemanner as in Example 8 except that after evaporating a Ti thin film(film thickness 0.1 μm) onto the surface of the insulating film on thesubstrate, a Ni thin film (film thickness 0.5 μm) was formed on the Tithin film by continuous evaporation and these thin films were etched bythe photolithographic method to form inner layers each consisting of alayered product of a Ti layer and a Ni layer, and then the layeredproducts were coated with Au layers that were outer layers to form thefirst and the second electrodes. The layered products were subjected tosubstitution-type gold plating for 10 minutes at 85° C., so that eventhe side faces of the Ti layers were plated with Au, and thus the entiresurfaces of the layered products were coated with the Au layers. Thethickness of the Au layer on the top face of the layered product wasabout 0.9 μm and the thickness of the Au layer on the side faces of thelayered product was about 0.9 μm.

Also in this example, a device in which the electrodes had good contactwith the conductive organic thin film as in the case of Example 10 wasobtained by coating the electrodes with the coating films.

Example 13

The compound expressed by the formula (10) was prepared by performingsyntheses in the same manner as in Example 1 except that 8-bromo-octanolwas used in place of 6-bromo-1-hexanol in the manufacturing step 1 ofPEN and 6-hexenylchloride was used in place of 10-undecenoilchloride inthe manufacturing step 4. A three-terminal organic electronic device wasproduced in the same manner as in Example 8 using this compound, and theobtained conductive organic thin film and three-terminal organicelectronic device showed the same results as in Example 8.

Example 14

The compound expressed by the formula (12) was prepared by performingsyntheses in the same manner as in Example 3 except that 8-bromo-octanolwas used in place of 6-bromo-1-hexanol in the manufacturing step 1 ofTEN and 6-hexenylchloride was used in place of 10-undecenoilchloride inthe manufacturing step 4. A three-terminal organic electronic device wasproduced in the same manner as in Example 10 using this compound, andthe obtained conductive organic thin film and three-terminal organicelectronic device showed the same results as in Example 10.

Example 15

A first and a second electrode were formed in the same manner as inExample 8 except that an insulative glass substrate was used as thesubstrate and no insulating film was formed. Then, polyacetylene-basedmonomolecular films for coating films were formed on the surfaces of theelectrodes in the following manner.

First, an acetylene derivative, (CH₃)₃Si—C≡C—(CH₂)₆—N═N—(CH₂)₈—SH, wasdissolved in an acetonitrile solvent to a concentration of 0.1 mol/L,and this acetylene solution was applied to the surfaces of the first andthe second electrodes on the substrate (applied thickness: about 10 μm)to be adsorbed. Then, after an adsorption reaction, the solvent wasremoved by washing to form acetylene derivative monomolecular films.Subsequently, the monomolecular films were irradiated with an electronbeam (100 Mrad) in a nitrogen atmosphere to polymerize the acetylene,and thus the surfaces of the electrodes were coated with polyacetylenemonomolecular films (thickness of about 1 nm).

Then, a two-terminal organic electronic device was produced in the samemanner as in Example 6 except that a substrate provided with theabove-described electrodes and coating films was used.

Also in this example, a two-terminal organic electronic device havingthe same properties as that of Example 6 was obtained. Moreover, thedevice in which the electrodes had good contact with the conductiveorganic thin film was obtained by coating the electrodes with thecoating films.

Example 16

First, electrodes were formed on a substrate in the same manner as inExample 15, and coating films were formed on the surfaces of theseelectrodes. Then, a two-terminal organic electronic device was producedin the same manner as in Example 7 except that the substrate providedwith the above-described electrodes and coating films was used.

Also in this example, a two-terminal organic electronic device havingthe same properties as that of Example 7 was obtained. Moreover, thedevice in which the electrodes had good contact with the conductiveorganic thin film was obtained by coating the electrodes with thecoating films.

Example 17

First, PEN was synthesized in the same manner as in Example 1. Then, anorganic electronic device (FET) was produced in the substantially samemanner as in Example 1 except that coating films were formed by thefollowing method, and the performance thereof was examined.

In this example, each of the electrodes had a structure in which thesurface of an inner layer formed of a Ni layer was coated with an outerlayer formed of an Au layer. Such electrodes were formed by the samemethod as that for forming the electrodes and the metal films forcoating in Example 1.

First, a thiol compound (4-mercapto-1-butanol: HO—(CH₂)₄—SH) having amercapto group in one end of a molecule and having a hydroxyl group inthe other end was added to 100 mL of butyl alcohol under a dryatmosphere to prepare a 0.01 mol/L solution. The substrate provided withthe electrodes was immersed in this solution for 30 minutes at 25° C.The substrate was pulled up from the solution, and butyl alcohol andunreacted thiol compound were removed from the surface of the substrateby drying.

By the above-described operation, a reaction occurred between the metalsconstituting the electrode and the mercapto groups (—SH) in the thiolcompound, and thus the thiol compound was adsorbed to the surface of theelectrode. Thus, monomolecular films constituted by molecules expressedby chemical formula (43) below that were chemically bonded to thesurfaces of the electrodes were formed as the coating films.HO—(CH₂)₄—S—  (43)

In this example, a large number of hydroxyl groups containing activehydrogen are present not only on the surface of the substrate but alsoon the surfaces of the coating films, so that when the substrateprovided with the above-described coating films and electrodes isimmersed in a chemisorption solution containing the PEN, adechlorination reaction occurs also on the surfaces of the coatingfilms. The chlorosilyl groups (—SiCl) in the substance are covalentlybonded to the surfaces of the coating films by this reaction.

As described above, the coating films that are chemically bonded to therespective electrodes and the conductive organic thin film are arrangedbetween the respective electrodes and the conductive organic thin film,and thus an organic electronic device having excellent connectivity ofthe electrodes with the conductive organic thin film can be obtained.

Moreover, when a compound expressed by chemical formula:HO—(CH₂)₆—COO—(CH₂)₄—SH or chemical formula: HO—(CH₂)₈—COO—(CH₂)₄—SH isused as a material for forming the coating films, excellent connectivitybetween the electrodes and the conductive organic thin film also can beachieved.

Example 18

First, TEN was synthesized in the same manner as in Example 3. Then, anorganic electronic device (FET) was produced in the same manner as inExample 17 except that this TEN was used, and the performance thereofwas examined.

Also in this example, coating films that are chemically bonded to therespective electrodes and the conductive organic thin film are arrangedbetween the respective electrodes and the conductive organic thin film,and thus an organic electronic device having excellent connectivitybetween the electrodes and the conductive organic thin film wasobtained.

Example 19

An organic electronic device was produced in the same manner as inExamples 17 and 18 except that the method for forming the coating filmswas different.

The method for forming molecular films for coating in this example is asfollows. First, a thiol compound (18-nonadecenylthiol:CH₂═CH—(CH₂)₁₇—SH) having a mercapto group in one end of a molecule andhaving a vinyl group in the other end was added to 100 mL ofacetonitrile to prepare a 1 wt % solution. The substrate provided withthe electrodes was immersed in this solution for 30 minutes at 25° C.Then, the substrate was pulled up from the solution, and the surface ofthe substrate was washed with chloroform.

By the above-described operation, a reaction occurred between the metalsconstituting the electrodes and the mercapto groups (—SH) in the thiolcompound, so that the thiol compound was adsorbed to the surfaces of theelectrodes. Thus, monomolecular films constituted by molecules expressedby chemical formula (44) below that were chemically bonded to thesurfaces of the electrodes were formed as precursors of the coatingfilms.CH₂═CH—(CH₂)₁₇—S—  (44)

Subsequently, the substrate provided with the precursors of the coatingfilms was immersed in a 5 mmol/L aqueous solution of permanganate for 24hours at room temperature. Then, the substrate was pulled up from thesolution and washed with water. Through this treatment, the vinyl groupsin the organic molecules constituting the precursors of the coatingfilms were oxidized and changed into groups containing active hydrogen(—OH groups). Thus, the coating films that were chemically bonded to thesurfaces of the electrodes and also had active hydrogen on theirsurfaces were formed.

When the substrate provided with such coating films is immersed in achemisorption solution containing organic molecules (PEN and TEN) thatare the same as those in Examples 17 and 18, since a large number ofhydroxyl groups containing active hydrogen are present on the surfacesof the coating films and the surface of the substrate, the chlorosilylgroups (—SiCl) in the organic molecules cause a dehydrochlorinationreaction with the hydroxyl groups to be covalently bonded to thesurfaces of the coating films and the surface of the substrate. Thus, asin the cases of Examples 17 and 18, a monomolecular film that was aprecursor thin film was formed on the surfaces of the coating films andthe surface of the substrate.

Moreover, the precursor thin film was polymerized to form a conductiveorganic thin film and an organic electronic device was produced, andthen it could be confirmed that an organic electronic device havingexcellent connectivity between the electrodes and the conductive organicthin film was obtained by arranging the coating films that werechemically bonded to the respective electrodes and the conductiveorganic thin film between the respective electrodes and the conductiveorganic thin film.

Moreover, it could be confirmed that when a compound expressed bychemical formula: CH₂═CH—(CH₂)₆—COO—(CH₂)₄—SH was used as a material forforming the coating films, excellent connectivity between the electrodesand the conductive organic thin film also was achieved.

Example 20

First, electrodes were formed on a substrate and coating films wereformed on the surfaces of these electrodes in the same manner as inExample 17. Then, a two-terminal organic electronic device was producedin the same manner as in Example 6 except that this substrate was used.

Also in this example, a two-terminal organic electronic device havingthe same properties as that of Example 6 was obtained. Moreover, thedevice in which the electrodes had good contact with the conductiveorganic thin film was obtained by coating the electrodes with thecoating films.

Example 21

First, electrodes were formed on a substrate and coating films wereformed on the surfaces of these electrodes in the same manner as inExample 18. Then, a two-terminal organic electronic device was producedin the same manner as in Example 7 except that the substrate providedwith the above-described electrodes and coating films was used.

Also in this example, a two-terminal organic electronic device havingthe same properties as that of Example 7 was obtained. Moreover, thedevice in which the electrodes had good contact with the conductiveorganic thin film was obtained by coating the electrodes with thecoating films.

INDUSTRIAL APPLICABILITY

The organic electronic device of the present invention has the coatingfilms for coating the surfaces of the electrodes, which electricallyconnect the electrodes to the conductive organic thin film and alsoreduce the connection resistance, so that the organic electronic devicehas excellent electrical connectivity between the electrodes and theconductive organic thin film. Furthermore, the conductive organic thinfilm is used for electrically connecting the electrodes, so that theorganic electronic device exhibits an excellent property of beingindependent of crystallinity, for example, even when further fineprocessing is performed to increase the density of the device. Such anorganic electronic device can be applied to, for example, variousapparatuses such as liquid display apparatuses, electroluminescentdisplay apparatuses, and electroluminescent elements, and is useful.

1. An organic electronic device comprising a substrate, at least twoelectrodes formed on the substrate, a conductive organic thin film thatis formed on the substrate and electrically connects the electrodes, anda coating film coating at least a portion of the electrodes, wherein theconductive organic thin film is a polymer of organic moleculescontaining a conjugated-bondable group, and one end of each of theorganic molecules is chemically bonded to the surface of the substrateand the conjugated-bondable groups in the organic molecules arepolymerized with other conjugated-bondable groups to form a conjugatedbond chain, and the coating film electrically connects the electrodes tothe conductive organic thin film and achieves a smaller connectionresistance than that in the case where the electrodes and the conductiveorganic thin film are connected directly.
 2. The organic electronicdevice according to claim 1, wherein the coating film is a metal film.3. The organic electronic device according to claim 2, wherein thecoating film is a metal film containing at least one selected from thegroup consisting of gold, platinum, and silver.
 4. The organicelectronic device according to claim 3, wherein the electrodes containat least one metal selected from the group consisting of Ni, Ti, indiumtin oxide (ITO), Cr, and W.
 5. The organic electronic device accordingto claim 4, wherein each of the electrodes is a single Ni layer or alayered product having a Ni layer as an uppermost layer.
 6. The organicelectronic device according to claim 1, wherein the coating film is aconductive polymeric film.
 7. The organic electronic device according toclaim 6, wherein the coating film is a conductive polymeric film basedon at least one selected from the group consisting of polypyrrole,polythiophene, polyaniline, polyacetylene, polydiacetylene, andpolyacene.
 8. The organic electronic device according to claim 6,wherein at least surface portions of the electrodes contain at least onemetal selected from the group consisting of gold, platinum, and silver.9. The organic electronic device according to claim 8, wherein each ofthe electrodes comprises an inner layer containing at least one metalselected from the group consisting of Ni, Ti, indium tin oxide (ITO), Crand W, and a gold layer, a platinum layer or a silver layer for coatingthe inner layer.
 10. The organic electronic device according to claim 9,wherein the inner layer is a single Ni layer or a layered product havinga Ni layer as an uppermost layer.
 11. The organic electronic deviceaccording to claim 1, wherein the coating film is a monomolecular filmthat is chemically bonded to the electrodes.
 12. The organic electronicdevice according to claim 11, wherein the coating film is amonomolecular film containing constituent molecules that are chemicallybonded to the surfaces of the electrodes by a —S— bond.
 13. The organicelectronic device according to claim 11, wherein at least a part of theconstituent molecules of the coating film are conjugated-bonded to theconjugated-bondable groups in the organic molecules constituting theconductive organic thin film.
 14. The organic electronic deviceaccording to claim 11, wherein the constituent molecule of the coatingfilm is selceted from the group consisting of pyrrole derivatives,thiopherte derivatives, aniline derivatives, acetylene derivatives, anddiacetylene derivatives containing a substituent that is bonded to thesurface of the electrode by a —S— bond.
 15. The organic electronicdevice according to claim 14, wherein the constituent molecule of thecoating film is a pyrrole derivative having a substituent that is bondedto the surface of the electrode by a —S— bond witb nitrogen (N) inposition 1 of a pyrrole ring.
 16. The organic electronic deviceaccording to claim 14, wherein the constituent molecule of the coatingfilm is a thiophene derivative having a substituent that is bonded tothe surface of the electrode by a —S— bond with at least one of carbons(C) in positions 3 and 4 of a thiophene ring.
 17. The organic electronicdevice according to claim 13, wherein the constituent molecules of thecoating film are polymerized by conjugated bonding.
 18. The organicelectronic device according to claim 11, wherein at least a part of theconstituent molecules of the coating film are covalently bonded toportions other than the conjugated-bondable groups in the organicmolecules constituting the conductive organic thin film.
 19. The organicelectronic device according to claim 18, wherein the constituentmolecules of the coating film and the organic molecules constituting theconductive organic thin film are bonded by at least one of a siloxanebond (—SiO—) and a —SiN— bond.
 20. The organic electronic deviceaccording to claim 11, wherein the constituent molecules of the coatingfilm are oriented.
 21. The organic electronic device according to claim11, wherein at least surface portions of the electrodes contain at leastone of metal selected from the group consisting of gold, platinum, andsilver.
 22. The organic electronic device according to claim 21, whereineach of the electrodes comprises an inner layer containing at least onemetal selected from the group consisting of Ni, Ti, indium tin oxide(ITO), Cr and W, and a gold layer, a platinum layer or a silver layerfor coating the inner layer.
 23. The organic electronic device accordingto claim 22, wherein the inner layer is a single Ni layer or a layeredproduct having a Ni layer as an uppermost layer.
 24. The organicelectronic dcvicc according to claim 1, wherein the conductive organicthin film is a monomolecular film or a monomolecular built-up film. 25.The organic electronic device according to claim 24, wherein the organicmolecules constituting the conductive organic thin film are oriented.26. The organic electronic device according to claim 1, wherein theconductive organic thin film has a conjugated bond chain polymerized byconjugated bonding of the organic molecules, and the conjugated bondchain is a chain of at least one selected from the group consisting ofpolypyrrole, polythiophene, polyacetylene, polydiacetylene, polyacene,polyphenylene, polyphenylenevinylene, polypyridinopyridine, andpolyaniline, and derivatives thereof.
 27. The organic electronic deviceaccording to claim 26, wherein the derivative of polyacetylene is atleast one group selected from the group consisting ofpolymethylacetylene, polybutylacetylene, polycyanoacetylene,polydicyanoacetylene, polypyridylacetylene, and polyphenylacetylene. 28.The organic electronic device according to claim 1, wherein a covalentbond between one end of the organic molecule constituting the conductivcorganic thin film and the surface of the substrate is at least one bondof a siloxane bond (—SiO—) and a —SiN— bond.
 29. The organic electronicdevice according to claim 1, wherein the organic molecule constitutingthe conductive organic thin film has a polar functional group containingno active hydrogen between a site that forms a covalent bond with thesurface of the substrate and a site that forms a conjugated bond withanother organic molecule.
 30. The organic electronic device according toclaim 29, wherein the polar functional group is at least one groupselected from the group consisting of an ester group (—COO—), anoxycarbonyl group (—OCO—), a carbonyl group (—CO—), and a carbonategroup (—OCOO—).
 31. The organic electronic device according to claim 29,wherein a unit of the polymer constituting the conductive organic thinfilm is at least one of units expressed by chemical formulae (1) and(2)below:

where X is hydrogen, an organic group containing an ester group, or anorganic group containing an unsaturated group, q is an integer of 0 to10, Z is an ester group (—COO—), an oxycarbonyl group (—OCO—), acarbonyl group (—CO—), or a carbonate group (—OCOO—), E is hydrogen oran alkyl group having 1 to 3 carbon atoms, m and n are integers and m+nis an integer of 2 to 25, and p is an integer of 1 to
 3. 32. The organicelectronic device according to claim 1, wherein the organic moleculeconstituting the conductive organic thin film has a photoresponsivefunctional group containing no active hydrogen between a site that formsa covalent bond with the surface of the substrate and a site that formsa conjugated bond with another organic molecule.
 33. The organicelectronic device according to claim 32, wherein the photoresponsivefunctional group is an azo group (—N═N—).
 34. The organic electronicdevice according to claim 32, wherein the unit of the polymerconstituting the conductive organic thin film is at least one of unitsexpressed by chemical formulae (3) and (4) below:

where X is hydrogen, an organic group containing an ester group or anorganic group containing an unsaturated group, q is an integer of 0 to10, E is hydrogen or an alkyl group having 1 to 3 carbon atoms, each sand t is an integer of 1 to 20, and p is an integer of 1 to
 3. 35. Theorganic electronic device according to claim 1, wherein the substrate isa substrate selected from the group consisting of glass, quartz, andplastics.
 36. The organic electronic device according to claim 1,wherein the surface of the substrate is coated with an oxide film, andthe surface of the oxide film, in place of the substrate, is covalentlybonded to one end of the organic molecule constituting the conductiveorganic thin film.
 37. The organic electronic device according to claim36, wherein the oxide film contains at least one inorganic oxideselected from the group consisting of SiO₂, Al₂O₃, Y₂O₃, ZrO₂, Ta₂O₅,La₂O₃, Nb₂O₃, TiO₂, barium zirconate titanate (BZT), and bariumstrontium titanale (BST).
 38. The organic electronic device according toclaim 36, wherein the oxide film comprises an organic oxide.
 39. Theorganic electronic device according to claim 1 further comprising athird electrode for controlling an electric field that acts on theconductive organic thin film.
 40. The organic electronic deviceaccording to claim 39, wherein the substrate is a silicon substrate, andthe conductive organic thin film is provided on the substrate via anoxide film, and the substrate functions as the third electrode forcontrolling the electric field that acts on the conductive organic thinfilm by applying a voltage between the two electrodes.